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Type/Module Description

Diff<'T>

Excel

F# Vector extensions

Defines non-generic `Vector` type that provides functions for building vectors (hard-bound to `ArrayVectorBuilder` type). In F#, the module is automatically opened using `AutoOpen`. The methods are not designed for the use from C#. Vectors and indices

F# Vector extensions (core)

Module with extensions for generic vector type. Given `vec` of type `IVector`, the extension property `vec.DataSequence` returns all data of the vector converted to the "least common denominator" data structure - `IEnumerable`. Vectors and indices

F# VectorBuilder implementation

Set concrete IVectorBuilder implementation Vectors and indices

IRangeRestriction<'TAddress>

A sequence of indicies together with the total number. Use `RangeRestriction.ofSeq` to create one from a sequence. This can be implemented by concrete vector/index builders to allow further optimizations (e.g. when the underlying source directly supports range operations). For example, if your source has an optimised way for getting every 10th address, you can create your own `IRangeRestriction` and then check for it in `LookupRange` and use optimised implementation rather than actually iterating over the sequence of indices.

IVector

Represents an (untyped) vector that stores some values and provides access to the values via a generic address. This type should be only used directly when extending the DataFrame library and adding a new way of storing or loading data. To allow invocation via Reflection, the vector exposes type of elements as `System.Type`. Vectors and indices

IVector<'T>

A generic, typed vector. Represents mapping from addresses to values of type `T`. The vector provides a minimal interface that is required by series and can be implemented in a number of ways to provide vector backed by database or an alternative representation of data. Vectors and indices

IVectorLocation

Represents a location in a vector. In general, we always know the address, but sometimes (BigDeedle) it is hard to get the offset (requires some data lookups), so we use this interface to delay the calculation of the Offset (which is mainly needed in one of the `series.Select` overloads) Vectors and indices

RangeRestriction

Provides additional operations for working with the `RangeRestriction<'TAddress>` type

RangeRestriction<'TAddress>

Specifies a sub-range within index that can be accessed via slicing (see the `GetAddressRange` method). For in-memory data structures, accessing range via known addresses is typically sufficient, but for virtual Big Deedle sources, `Start` and `End` let us avoid fully evaluating addresses. `Custom` range can be used for optimizations.

SeriesStatsExtensions

The type implements C# and F# extension methods that add numerical operations to Deedle series. Frame and series operations

StatsInternal

VectorCallSite<'R>

Represents a generic function `\forall.'T.(IVector<'T> -> 'R)`. The function can be generically invoked on an argument of type `IVector` using `IVector.Invoke` Vectors and indices

Core frame and series types

Type/Module Description

F# Series extensions

Contains extensions for creating values of type Series<'K, 'V> including a type with functions such as `Series.ofValues` and the `series` function. The module is automatically opened for all F# code that references `Deedle`.

Frame<'TRowKey, 'TColumnKey>

A frame is the key Deedle data structure (together with series). It represents a data table (think spreadsheet or CSV file) with multiple rows and columns. The frame consists of row index, column index and data. The indices are used for efficient lookup when accessing data by the row key `'TRowKey` or by the column key `'TColumnKey`. Deedle frames are optimized for the scenario when all values in a given column are of the same type (but types of different columns can differ).

FrameData

Represents the underlying (raw) data of the frame in a format that can be used for exporting data frame to other formats etc. (DataTable, CSV, Excel)

ISeries<'K>

Represents an untyped series with keys of type `K` and values of some unknown type (This type should not generally be used directly, but it can be used when you need to write code that works on a sequence of series of heterogeneous types).

Series<'K, 'V>

The type Series<K, V> represents a data series consisting of values `V` indexed by keys `K`. The keys of a series may or may not be ordered

Frame and series operations

Type/Module Description

EnumerableExtensions

Contains C#-friendly extension methods for various instances of `IEnumerable` that can be used for creating Series<'K, 'V> from the `IEnumerable` value. You can create an ordinal series from IEnumerable<'T> or an indexed series from IEnumerable<KeyValuePair<'K, 'V>> or from IEnumerable<KeyValuePair<'K, OptionalValue<'V>>>.

F# Frame extensions

This module contains F# functions and extensions for working with frames. This includes operations for creating frames such as the `frame` function, `=>` operator and `Frame.ofRows`, `Frame.ofColumns` and `Frame.ofRowKeys` functions. The module also provides additional F# extension methods including `ReadCsv`, `SaveCsv` and `PivotTable`.

Frame (Module)

The `Frame` module provides an F#-friendly API for working with data frames. The module follows the usual desing for collection-processing in F#, so the functions work well with the pipelining operator (`|>`). For example, given a frame with two columns representing prices, we can use `Frame.pctChange` to calculate daily returns like this: let df = frame [ "MSFT" => prices1; "AAPL" => prices2 ] let rets = df |> Frame.pctChange 1 rets |> Stats.mean Note that the `Stats.mean` operation is overloaded and works both on series (returning a number) and on frames (returning a series). You can also use `Frame.diff` if you need absolute differences rather than relative changes. The functions in this module are designed to be used from F#. For a C#-friendly API, see the `FrameExtensions` type. For working with individual series, see the `Series` module. The functions in the `Frame` module are grouped in a number of categories and documented below. Accessing frame data and lookup ------------------------------- Functions in this category provide access to the values in the fame. You can also add and remove columns from a frame (which both return a new value). - `addCol`, `replaceCol` and `dropCol` can be used to create a new data frame with a new column, by replacing an existing column with a new one, or by dropping an existing column - `cols` and `rows` return the columns or rows of a frame as a series containing objects; `getCols` and `getRows` return a generic series and cast the values to the type inferred from the context (columns or rows of incompatible types are skipped); `getNumericCols` returns columns of a type convertible to `float` for convenience. - You can get a specific row or column using `get[Col|Row]` or `lookup[Col|Row]` functions. The `lookup` variant lets you specify lookup behavior for key matching (e.g. find the nearest smaller key than the specified value). There are also `[try]get` and `[try]Lookup` functions that return optional values and functions returning entire observations (key together with the series). - `sliceCols` and `sliceRows` return a sub-frame containing only the specified columns or rows. Finally, `toArray2D` returns the frame data as a 2D array. Grouping, windowing and chunking -------------------------------- The basic grouping functions in this category can be used to group the rows of a data frame by a specified projection or column to create a frame with hierarchical index such as Frame<'K1 * 'K2, 'C>. The functions always aggregate rows, so if you want to group columns, you need to use `Frame.transpose` first. The function `groupRowsBy` groups rows by the value of a specified column. Use `groupRowsBy[Int|Float|String...]` if you want to specify the type of the column in an easier way than using type inference; `groupRowsUsing` groups rows using the specified _projection function_ and `groupRowsByIndex` projects the grouping key just from the row index. More advanced functions include: `aggregateRowsBy` which groups the rows by a specified sequence of columns and aggregates each group into a single value; `pivotTable` implements the pivoting operation [as documented in the tutorials](../frame.html#pivot). The `melt` and `unmelt` functions turn the data frame into a single data frame containing columns `Row`, `Column` and `Value` containing the data of the original frame; `melt` can be used to turn this representation back into an original frame. A simple windowing functions that are exposed for an entire frame operations are `window` and `windowInto`. For more complex windowing operations, you currently have to use `mapRows` or `mapCols` and apply windowing on individual series. Sorting and index manipulation ------------------------------ A frame is indexed by row keys and column keys. Both of these indices can be sorted (by the keys). A frame that is sorted allows a number of additional operations (such as lookup using the `Lookp.ExactOrSmaller` lookup behavior). The functions in this category provide ways for manipulating the indices. It is expected that most operations are done on rows and so more functions are available in a row-wise way. A frame can alwyas be transposed using `Frame.transpose`. Index operations: The existing row/column keys can be replaced by a sequence of new keys using the `indexColsWith` and `indexRowsWith` functions. Row keys can also be replaced by ordinal numbers using `indexRowsOrdinally`. The function `indexRows` uses the specified column of the original frame as the index. It removes the column from the resulting frame (to avoid this, use overloaded `IndexRows` method). This function infers the type of row keys from the context, so it is usually more convenient to use `indexRows[Date|String|Int|...]` functions. Finally, if you want to calculate the index value based on multiple columns of the row, you can use `indexRowsUsing`. Sorting frame rows: Frame rows can be sorted according to the value of a specified column using the `sortRows` function; `sortRowsBy` takes a projection function which lets you transform the value of a column (e.g. to project a part of the value). The functions `sortRowsByKey` and `sortColsByKey` sort the rows or columns using the default ordering on the key values. The result is a frame with ordered index. Expanding columns: When the frame contains a series with complex .NET objects such as F# records or C# classes, it can be useful to "expand" the column. This operation looks at the type of the objects, gets all properties of the objects (recursively) and generates multiple series representing the properties as columns. The function `expandCols` expands the specified columns while `expandAllCols` applies the expansion to all columns of the data frame. Frame transformations --------------------- Functions in this category perform standard transformations on data frames including projections, filtering, taking some sub-frame of the frame, aggregating values using scanning and so on. Projection and filtering functions such as `[map|filter][Cols|Rows]` call the specified function with the column or row key and an ObjectSeries<'K> representing the column or row. You can use functions ending with `Values` (such as `mapRowValues`) when you do not require the row key, but only the row series; `mapRowKeys` and `mapColKeys` can be used to transform the keys. You can use `reduceValues` to apply a custom reduction to values of columns. Other aggregations are available in the `Stats` module. You can also get a row with the greaterst or smallest value of a given column using `[min|max]RowBy`. The functions `take[Last]` and `skip[Last]` can be used to take a sub-frame of the original source frame by skipping a specified number of rows. Note that this does not require an ordered frame and it ignores the index - for index-based lookup use slicing, such as `df.Rows.[lo .. hi]`, instead. Finally the `shift` function can be used to obtain a frame with values shifted by the specified offset. This can be used e.g. to get previous value for each key using `Frame.shift 1 df`. The `diff` function calculates difference from previous value using `df - (Frame.shift offs df)`. Processing frames with exceptions --------------------------------- The functions in this group can be used to write computations over frames that may fail. They use the type tryval<'T> which is defined as a discriminated union with two cases: Success containing a value, or Error containing an exception. Using tryval<'T> as a value in a data frame is not generally recommended, because the type of values cannot be tracked in the type. For this reason, it is better to use tryval<'T> with individual series. However, `tryValues` and `fillErrorsWith` functions can be used to get values, or fill failed values inside an entire data frame. The `tryMapRows` function is more useful. It can be used to write a transformation that applies a computation (which may fail) to each row of a data frame. The resulting series is of type Series<'R, tryval<'T>> and can be processed using the Series module functions. Missing values -------------- This group of functions provides a way of working with missing values in a data frame. The category provides the following functions that can be used to fill missing values: * `fillMissingWith` fills missing values with a specified constant * `fillMissingUsing` calls a specified function for every missing value * `fillMissing` and variants propagates values from previous/later keys We use the terms _sparse_ and _dense_ to denote series that contain some missing values or do not contain any missing values, respectively. The functions `denseCols` and `denseRows` return a series that contains only dense columns or rows and all sparse rows or columns are replaced with a missing value. The `dropSparseCols` and `dropSparseRows` functions drop these missing values and return a frame with no missing values. Joining, merging and zipping ---------------------------- The simplest way to join two frames is to use the `join` operation which can be used to perform left, right, outer or inner join of two frames. When the row keys of the frames do not match exactly, you can use `joinAlign` which takes an additional parameter that specifies how to find matching key in left/right join (e.g. by taking the nearest smaller available key). Frames that do not contian overlapping values can be combined using `merge` (when combining just two frames) or using `mergeAll` (for larger number of frames). Tha latter is optimized to work well for a large number of data frames. Finally, frames with overlapping values can be combined using `zip`. It takes a function that is used to combine the overlapping values. A `zipAlign` function provides a variant with more flexible row key matching (as in `joinAlign`) Hierarchical index operations ----------------------------- A data frame has a hierarchical row index if the row index is formed by a tuple, such as Frame<'R1 * 'R2, 'C>. Frames of this kind are returned, for example, by the grouping functions such as Frame.groupRowsBy. The functions in this category provide ways for working with data frames that have hierarchical row keys. The functions applyLevel and reduceLevel can be used to reduce values according to one of the levels. The applyLevel function takes a reduction of type Series<'K, 'T> -> 'T while reduceLevel reduces individual values using a function of type 'T -> 'T -> 'T. The functions nest and unnest can be used to convert between frames with hierarchical indices (Frame<'K1 * 'K2, 'C>) and series of frames that represent individual groups (Series<'K1, Frame<'K2, 'C>>). The nestBy function can be used to perform group by operation and return the result as a series of frems.

Frame (Type)

Provides static methods for creating frames, reading frame data from CSV files and database (via IDataReader). The type also provides global configuration for reflection-based expansion.

FrameBuilder

Type that can be used for creating frames using the C# collection initializer syntax. You can use new FrameBuilder.Columns<...> to create a new frame from columns or you can use new FrameBuilder.Rows<...> to create a new frame from rows.

FrameExtensions

Contains C# and F# extension methods for the `Frame<'R, 'C>` type. The members are automatically available when you import the `Deedle` namespace. The type contains object-oriented counterparts to most of the functionality from the `Frame` module.

FrameStatsExtensions

The type implements C# and F# extension methods that add numerical operations to Deedle series. With a few exceptions, the methods are only available for series containing floating-point values, that is Series<'K, float>.

Series

The `Series` module provides an F#-friendly API for working with data and time series. The API follows the usual design for collection-processing in F#, so the functions work well with the pipelining (|>) operator. For example, given a series with ages, we can use `Series.filterValues` to filter outliers and then `Stats.mean` to calculate the mean: ages |> Series.filterValues (fun v -> v > 0.0 && v < 120.0) |> Stats.mean The module provides comprehensive set of functions for working with series. The same API is also exposed using C#-friendly extension methods. In C#, the above snippet could be written as: [lang=csharp] ages .Where(kvp => kvp.Value > 0.0 && kvp.Value < 120.0) .Mean() For more information about similar frame-manipulation functions, see the `Frame` module. For more information about C#-friendly extensions, see `SeriesExtensions`. The functions in the `Series` module are grouped in a number of categories and documented below. Accessing series data and lookup -------------------------------- Functions in this category provide access to the values in the series. - The term _observation_ is used for a key value pair in the series. - When working with a sorted series, it is possible to perform lookup using keys that are not present in the series - you can specify to search for the previous or next available value using _lookup behavior_. - Functions such as `get` and `getAll` have their counterparts `lookup` and `lookupAll` that let you specify lookup behavior. - For most of the functions that may fail, there is a `try[Foo]` variant that returns `None` instead of failing. - Functions with a name ending with `At` perform lookup based on the absolute integer offset (and ignore the keys of the series) Series transformations ---------------------- Functions in this category perform standard transformations on series including projections, filtering, taking some sub-series of the series, aggregating values using scanning and so on. Projection and filtering functions generally skip over missing values, but there are variants `filterAll` and `mapAll` that let you handle missing values explicitly. Keys can be transformed using `mapKeys`. When you do not need to consider the keys, and only care about values, use `filterValues` and `mapValues` (which is also aliased as the `$` operator). Series supports standard set of folding functions including `reduce` and `fold` (to reduce series values into a single value) as well as the `scan[All]` function, which can be used to fold values of a series into a series of intermeidate folding results. The functions `take[Last]` and `skip[Last]` can be used to take a sub-series of the original source series by skipping a specified number of elements. Note that this does not require an ordered series and it ignores the index - for index-based lookup use slicing, such as `series.[lo .. hi]`, instead. Finally the `shift` function can be used to obtain a series with values shifted by the specified offset. This can be used e.g. to get previous value for each key using `Series.shift 1 ts`. The `diff` function calculates difference from previous value using `ts - (Series.shift offs ts)`. Processing series with exceptions --------------------------------- The functions in this group can be used to write computations over series that may fail. They use the type tryval<'T> which is defined as a discriminated union with two cases: Success containing a value, or Error containing an exception. The function `tryMap` lets you create Series<'K, tryval<'T>> by mapping over values of an original series. You can then extract values using `tryValues`, which throws `AggregateException` if there were any errors. Functions `tryErrors` and `trySuccesses` give series containing only errors and successes. You can fill failed values with a constant using `fillErrorsWith`. Hierarchical index operations ----------------------------- When the key of a series is tuple, the elements of the tuple can be treated as multiple levels of a index. For example Series<'K1 * 'K2, 'V> has two levels with keys of types 'K1 and 'K2 respectively. The functions in this cateogry provide a way for aggregating values in the series at one of the levels. For example, given a series `input` indexed by two-element tuple, you can calculate mean for different first-level values as follows: input |> applyLevel fst Stats.mean Note that the `Stats` module provides helpers for typical statistical operations, so the above could be written just as `input |> Stats.levelMean fst`. Grouping, windowing and chunking -------------------------------- This category includes functions that group data from a series in some way. Two key concepts here are _window_ and _chunk_. Window refers to (overlapping) sliding windows over the input series while chunk refers to non-overlapping blocks of the series. The boundary behavior can be specified using the `Boundary` flags. The value `Skip` means that boundaries (incomplete windows or chunks) should be skipped. The value `AtBeginning` and `AtEnding` can be used to define at which side should the boundary be returned (or skipped). For chunking, `AtBeginning ||| Skip` makes sense and it means that the incomplete chunk at the beginning should be skipped (aligning the last chunk with the end). The behavior may be specified in a number of ways (which is reflected in the name): - `dist` - using an absolute distance between the keys - `while` - using a condition on the first and last key - `size` - by specifying the absolute size of the window/chunk The functions ending with `Into` take a function to be applied to the window/chunk. The functions `window`, `windowInto` and `chunk`, `chunkInto` are simplified versions that take a size. There is also `pairwise` function for sliding window of size two. Missing values -------------- This group of functions provides a way of working with missing values in a series. The `dropMissing` function drops all keys for which there are no values in the series. The `withMissingFrom` function lets you copy missing values from another series. The remaining functions provide different mechanism for filling the missing values. * `fillMissingWith` fills missing values with a specified constant * `fillMissingUsing` calls a specified function for every missing value * `fillMissing` and variants propagates values from previous/later keys Sorting and index manipulation ------------------------------ A series that is sorted by keys allows a number of additional operations (such as lookup using the `Lookp.ExactOrSmaller` lookup behavior). However, it is also possible to sort series based on the values - although the functions for manipulation with series do not guarantee that the order will be preserved. To sort series by keys, use `sortByKey`. Other sorting functions let you sort the series using a specified comparer function (`sortWith`), using a projection function (`sortBy`) and using the default comparison (`sort`). In addition, you can also replace the keys of a series with other keys using `indexWith` or with integers using `indexOrdinally`. To pick and reorder series values using to match a list of keys use `realign`. Sampling, resampling and advanced lookup ---------------------------------------- Given a (typically) time series sampling or resampling makes it possible to get time series with representative values at lower or uniform frequency. We use the following terminology: - `lookup` and `sample` functions find values at specified key; if a key is not available, they can look for value associated with the nearest smaller or the nearest greater key. - `resample` function aggregate values values into chunks based on a specified collection of keys (e.g. explicitly provided times), or based on some relation between keys (e.g. date times having the same date). - `resampleUniform` is similar to resampling, but we specify keys by providing functions that generate a uniform sequence of keys (e.g. days), the operation also fills value for days that have no corresponding observations in the input sequence. Joining, merging and zipping ---------------------------- Given two series, there are two ways to combine the values. If the keys in the series are not overlapping (or you want to throw away values from one or the other series), then you can use `merge` or `mergeUsing`. To merge more than 2 series efficiently, use the `mergeAll` function, which has been optimized for large number of series. If you want to align two series, you can use the _zipping_ operation. This aligns two series based on their keys and gives you tuples of values. The default behavior (`zip`) uses outer join and exact matching. For ordered series, you can specify other forms of key lookups (e.g. find the greatest smaller key) using `zipAlign`. functions ending with `Into` are generally easier to use as they call a specified function to turn the tuple (of possibly missing values) into a new value. For more complicated behaviors, it is often convenient to use joins on frames instead of working with series. Create two frames with single columns and then use the join operation. The result will be a frame with two columns (which is easier to use than series of tuples).

SeriesExtensions

The type implements C# and F# extension methods for the Series<'K, 'V> type. The members are automatically available when you import the `Deedle` namespace. The type contains object-oriented counterparts to most of the functionality from the `Series` module.

Stats

The `Stats` type contains functions for fast calculation of statistics over series and frames as well as over a moving and an expanding window in a series. The resulting series has the same keys as the input series. When there are no values, or missing values, different functions behave in different ways. Statistics (e.g. mean) return missing value when any value is missing, while min/max functions return the minimal/maximal element (skipping over missing values).

Parameters and results of various operations

Type/Module Description

Aggregation

A non-generic type that simplifies the construction of Aggregation<K> values from C#. It provides methods for constructing different kinds of aggregation strategies for ordered series.

Aggregation<'K>

Represents a strategy for aggregating data in an ordered series into data segments. To create a value of this type from C#, use the non-generic `Aggregation` type. Data can be aggregate using floating windows or chunks of a specified size or by specifying a condition on two keys (i.e. end a window/chunk when the condition no longer holds).

Boundary

Represents boundary behaviour for operations such as floating window. The type specifies whether incomplete windows (of smaller than required length) should be produced at the beginning (`AtBeginning`) or at the end (`AtEnding`) or skipped (`Skip`). For chunking, combinations are allowed too - to skip incomplete chunk at the beginning, use `Boundary.Skip ||| Boundary.AtBeginning`.

ConversionKind

Represents different kinds of type conversions that can be used by Deedle internally. This is used, for example, when converting ObjectSeries<'K> to Series<'K, 'T> - The conversion kind can be specified as an argument to allow certain conversions.

DataSegment

Provides helper functions and active patterns for working with `DataSegment` values

DataSegment<'T>

Represents a segment of a series or sequence. The value is returned from various functions that aggregate data into chunks or floating windows. The `Complete` case represents complete segment (e.g. of the specified size) and `Boundary` represents segment at the boundary (e.g. smaller than the required size).

DataSegmentKind

Represents a kind of DataSegment<T>. See that type for more information.

Direction

Specifies in which direction should we look when performing operations such as `Series.Pairwise`.

ICustomLookup<'K>

Represents a special lookup. This can be used to support hierarchical or duplicate keys in an index. A key type `K` can come with associated ICustomLookup<K> to provide customized pattern matching (equality testing)

JoinKind

This enumeration specifies joining behavior for `Join` method provided by `Series` and `Frame`. Outer join unions the keys (and may introduce missing values), inner join takes the intersection of keys; left and right joins take the keys of the first or the second series/frame.

Lookup

Represents different behaviors of key lookup in series. For unordered series, the only available option is `Lookup.Exact` which finds the exact key - methods fail or return missing value if the key is not available in the index. For ordered series `Lookup.Greater` finds the first greater key (e.g. later date) with a value. `Lookup.Smaller` searches for the first smaller key. The options `Lookup.ExactOrGreater` and `Lookup.ExactOrSmaller` finds the exact key (if it is present) and otherwise search for the nearest larger or smaller key, respectively.

MultiKeyExtensions

F#-friendly functions for creating multi-level keys and lookups

UnionBehavior

This enumeration specifies the behavior of `Union` operation on series when there are overlapping keys in two series that are being unioned. The options include preferring values from the left/right series or throwing an exception when both values are available.

Primitive types and values

Type/Module Description

KeyValue

A type with extension method for KeyValuePair<'K, 'V> that makes it possible to create values using just `KeyValue.Create`.

MissingValueException

Thrown when a value at the specified index does not exist in the data frame or series. This exception is thrown only when the key is defined, but the value is not available, in other situations `KeyNotFoundException` is thrown

'T opt

A type alias for the OptionalValue<T> type. The type alias can be used to make F# type definitions that use optional values directly more succinct.

OptionalValue (Module)

Provides various helper functions for using the OptionalValue<T> type from F# (The functions are similar to those in the standard Option module).

OptionalValue (Type)

Non-generic type that makes it easier to create OptionalValue<T> values from C# by benefiting the type inference for generic method invocations.

OptionalValue<'T>

Value type that represents a potentially missing value. This is similar to System.Nullable<T>, but does not restrict the contained value to be a value type, so it can be used for storing values of any types. When obtained from DataFrame<R, C> or Series<K, T>, the Value will never be Double.NaN or null (but this is not, in general, checked when constructing the value). The type is only used in C#-friendly API. F# operations generally use expose standard F# option<T> type instead. However, there the OptionalValue module contains helper functions for using this type from F# as well as Missing and Present active patterns.

OptionalValueExtensions

Extension methods for working with optional values from C#. These make it easier to provide default values and convert optional values to `Nullable` (when the contained value is value type)

Pair

Module with helper functions for extracting values from hierarchical tuples

'T tryval

A type alias for the TryValue<T> type. The type alias can be used to make F# type declarations that explcitly handle exceptions more succinct.

TryValue<'T>

Represents a value or an exception. This type is used by functions such as `Series.tryMap` and `Frame.tryMap` to capture the result of a lambda function, which may be either a value or an exception. The type is a discriminated union, so it can be processed using F# pattern matching, or using `Value`, `HasValue` and `Exception` properties

Specialized frame and series types

Type Description

ColumnSeries<'TRowKey, 'TColumnKey>

Represents a series of columns from a frame. The type inherits from a series of series representing individual columns (Series<'TColumnKey, ObjectSeries<'TRowKey>>) but hides slicing operations with new versions that return frames.

DelayedSeries

This type exposes a single static method `DelayedSeries.Create` that can be used for constructing data series (of type Series<K, V>) with lazily loaded data. You can use this functionality to create series that represents e.g. an entire price history in a database, but only loads data that are actually needed. For more information see the [lazy data loading tutorial](../lazysource.html).

IFrame

An empty interface that is implemented by Frame<'R, 'C>. The purpose of the interface is to allow writing code that works on arbitrary data frames (you need to provide an implementation of the IFrameOperation<'V> which contains a generic method `Invoke` that will be called with the typed data frame).

IFrameOperation<'V>

Represents an operation that can be invoked on Frame<'R, 'C>. The operation is generic in the type of row and column keys.

ObjectSeries<'K>

Represents a series containing boxed values. This type is inherited from Series<'K, obj> and it adds additional operations for accessing values with unboxing. This includes operations such as os.GetAs<'T>, os.TryGetAs<'T> and os.TryAs<'T> which (attempt to) convert values to the specified type `'T`.

RowSeries<'TRowKey, 'TColumnKey>

Represents a series of rows from a frame. The type inherits from a series of series representing individual rows (Series<'TRowKey, ObjectSeries<'TColumnKey>>) but hides slicing operations with new versions that return frames.

SeriesBuilder<'K>

A simple class that inherits from SeriesBuilder<'K, obj> and can be used instead of writing SeriesBuilder<'K, obj> with two type arguments.

SeriesBuilder<'K, 'V>

The type can be used for creating series using mutation. You can add items using `Add` and get the resulting series using the Series property.

Vectors and indices

Type/Module Description

Addressing

An `Address` value is used as an interface between vectors and indices. The index maps keys of various types to address, which is then used to get a value from the vector. Here is a brief summary of what we assume (and don't assume) about addresses: - Address is `int64` (although we might need to generalize this in the future) - Different data sources can use different addressing schemes (as long as both index and vector use the same scheme) - Addresses don't have to be continuous (e.g. if the source is partitioned, it can use 32bit partition index + 32bit offset in the partition) - In the in-memory representation, address is just index into an array - In the BigDeedle representation, address is abstracted and comes with `AddressOperations` that specifies how to use it (tests use linear offset and partitioned representation)

F# Index extensions

Defines non-generic `Index` type that provides functions for building indices (hard-bound to `LinearIndexBuilder` type). In F#, the module is automatically opened using `AutoOpen`. The methods are not designed for the use from C#.

F# IndexBuilder implementation

Set concrete IIndexBuilder implementation

Index

Type that provides access to creating indices (represented as `LinearIndex` values)

Type something to start searching.