### Table Of Contents

- Array creation routines
  - Ones and zeros
  - From existing data
  - Creating record arrays (`numpy.rec`)
  - Creating character arrays (`numpy.char`)
  - Numerical ranges
  - Building matrices
  - The Matrix class

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# Array creation routines

See also

Array creation

## Ones and zeros

`empty`(shape[, dtype, order]) | Return a new array of given shape and type, without initializing entries.
`empty_like`(a[, dtype, order, subok]) | Return a new array with the same shape and type as a given array.
`eye`(N[, M, k, dtype]) | Return a 2-D array with ones on the diagonal and zeros elsewhere.
`identity`(n[, dtype]) | Return the identity array.
`ones`(shape[, dtype, order]) | Return a new array of given shape and type, filled with ones.
`ones_like`(a[, dtype, order, subok]) | Return an array of ones with the same shape and type as a given array.
`zeros`(shape[, dtype, order]) | Return a new array of given shape and type, filled with zeros.
`zeros_like`(a[, dtype, order, subok]) | Return an array of zeros with the same shape and type as a given array.
`full`(shape, fill_value[, dtype, order]) | Return a new array of given shape and type, filled with fill_value.
`full_like`(a, fill_value[, dtype, order, subok]) | Return a full array with the same shape and type as a given array.

## From existing data

`array`(object[, dtype, copy, order, subok, ndmin]) | Create an array.
`asarray`(a[, dtype, order]) | Convert the input to an array.
`asanyarray`(a[, dtype, order]) | Convert the input to an ndarray, but pass ndarray subclasses through.
`ascontiguousarray`(a[, dtype]) | Return a contiguous array in memory (C order).
`asmatrix`(data[, dtype]) | Interpret the input as a matrix.
`copy`(a[, order]) | Return an array copy of the given object.
`frombuffer`(buffer[, dtype, count, offset]) | Interpret a buffer as a 1-dimensional array.
`fromfile`(file[, dtype, count, sep]) | Construct an array from data in a text or binary file.
`fromfunction`(function, shape, **kwargs) | Construct an array by executing a function over each coordinate.
`fromiter`(iterable, dtype[, count]) | Create a new 1-dimensional array from an iterable object.
`fromstring`(string[, dtype, count, sep]) | A new 1-D array initialized from raw binary or text data in a string.
`loadtxt`(fname[, dtype, comments, delimiter, ...]) | Load data from a text file.

## Creating record arrays (`numpy.rec`)

Note

`numpy.rec` is the preferred alias for `numpy.core.records`.

`core.records.array`(obj[, dtype, shape, ...]) | Construct a record array from a wide-variety of objects.
`core.records.fromarrays`(arrayList[, dtype, ...]) | create a record array from a (flat) list of arrays
`core.records.fromrecords`(recList[, dtype, ...]) | create a recarray from a list of records in text form
`core.records.fromstring`(datastring[, dtype, ...]) | create a (read-only) record array from binary data contained in
`core.records.fromfile`(fd[, dtype, shape, ...]) | Create an array from binary file data If file is a string then that file is opened, else it is assumed to be a file object.

## Creating character arrays (`numpy.char`)

Note

`numpy.char` is the preferred alias for `numpy.core.defchararray`.

`core.defchararray.array`(obj[, itemsize, ...]) | Create a `chararray`.
`core.defchararray.asarray`(obj[, itemsize, ...]) | Convert the input to a `chararray`, copying the data only if necessary.

## Numerical ranges

`arange`([start,] stop[, step,][, dtype]) | Return evenly spaced values within a given interval.
`linspace`(start, stop[, num, endpoint, ...]) | Return evenly spaced numbers over a specified interval.
`logspace`(start, stop[, num, endpoint, base, ...]) | Return numbers spaced evenly on a log scale.
`meshgrid`(*xi, **kwargs) | Return coordinate matrices from coordinate vectors.
`mgrid` | nd_grid instance which returns a dense multi-dimensional “meshgrid”.
`ogrid` | nd_grid instance which returns an open multi-dimensional “meshgrid”.

## Building matrices

`diag`(v[, k]) | Extract a diagonal or construct a diagonal array.
`diagflat`(v[, k]) | Create a two-dimensional array with the flattened input as a diagonal.
`tri`(N[, M, k, dtype]) | An array with ones at and below the given diagonal and zeros elsewhere.
`tril`(m[, k]) | Lower triangle of an array.
`triu`(m[, k]) | Upper triangle of an array.
`vander`(x[, N, increasing]) | Generate a Vandermonde matrix.

## The Matrix class

`mat`(data[, dtype]) | Interpret the input as a matrix.
`bmat`(obj[, ldict, gdict]) | Build a matrix object from a string, nested sequence, or array.