Class np.OGridClass

Namespace

NumSharp

Assembly

NumSharp.dll

An instance which returns an open multi-dimensional "meshgrid" when indexed, so that only one dimension of each returned array is greater than 1. The number and dimensionality of the outputs equal the number of indexing slices. If the step length is not a complex number, the stop is NOT inclusive; a complex step (e.g. "…:5j") instead specifies the number of points, with the stop INCLUSIVE (i.e. linspace(double, double, long, bool, DType, string)).

public sealed class np.OGridClass

Inheritance

object

np.OGridClass

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

NDArray x   = np.ogrid["-1:1:5j"];         // array([-1., -0.5, 0., 0.5, 1.])
var (y, xx) = np.ogrid["0:5", "0:5"];      // y.shape (5,1), xx.shape (1,5)
NDArray[] g = np.ogrid["0:3", "0:4", "0:5"];
NDArray sum = np.ogrid["0:5", "0:5"][0] + np.ogrid["0:5", "0:5"][1];  // broadcast add

Remarks

Port of NumPy 2.x numpy.ogrid (the sparse=True instance of numpy.lib.index_tricks.nd_grid). It shares the slice-expression grammar of r_: C# has no a[1:5:2] literal, so a slice is written as a string — np.ogrid["0:5"] ≙ np.ogrid[0:5] — and one string may carry several comma-separated slices (np.ogrid["0:3, 0:5"]). Slice objects work as entries too. Unlike r_ there are NO leading directives: every entry is a slice.

Dtype. All the slices of a multi-slice mesh share ONE dtype — int64 when every field of every slice is an integer literal, else float64 (a complex step counts as non-integer). This mirrors NumPy's single result_type(*num_list) over all the slice bounds: e.g. np.ogrid["0:2", "0.0:2"] gives two float64 arrays, not one int64 and one float64. A single-slice result keeps the literal-driven dtype of r_'s slice branch.

Missing stop. A single slice may omit its stop (np.ogrid["5:"] is arange(0, 5), exactly like r_). A multi-slice mesh may NOT: NumPy needs the stop to size each axis and leaks an AttributeError when it is absent, so NumSharp raises a clear ValueError for np.ogrid["0:3", "5:"]. An imaginary step always requires a stop (single or multi), also a ValueError.

Return. The np.OGridResult stands in for NumPy's array-or-tuple: a single-slice result converts implicitly to a bare NDArray; a multi-slice result converts to NDArray[], deconstructs, or indexes.

https://numpy.org/doc/stable/reference/generated/numpy.ogrid.html

Properties

this[object[]]

Expands the slice expression into an open mesh. See np.OGridClass for how a Python slice literal is spelled in C#.

public np.OGridResult this[params object[] key] { get; }

Parameters

key object[]

Slice-expression strings (a colon-bearing "start:stop[:step]", or several such comma-separated), and/or Slice objects.

Property Value

np.OGridResult