#include "array.h"
#include "helper.h"
#include <stdarg.h>
#include <string.h>
#include <gsl/gsl_rng.h>
#include <time.h>

Functions
void	array_calc_colindex (ulong offset, const uint size, uint nsize, uint index)
	calculate the column-major index-tuple given the offset from element 0.
void	array_calc_rowindex (ulong offset, const uint size, uint nsize, uint index)
	calculate the row-major index-tuple given the offset from element 0.
bool	array_comparable (const Array a, const Array b)
	Compare two array's dimensions and datatype.
Array *	array_concatenate (const Array a, const Array b, int dim)
	concatenate two arrays.
Array *	array_convert_rowcolmajor (Array *a, bool alloc)
	convert a row-major array to col-major.
Array *	array_copy (const Array *in, bool allocdata)
	makes a copy of an array.
int	array_dimred (Array *a)
	Delete unnecessary dimensions (of size 1).
void	array_dtype_to_double (double out, void mem, DType dt)
	cast memory of type dt in location mem to double.
void	array_free (Array *a)
	free all memory associated with the array.
Array *	array_fromptr (DType dtype, uint ndim, void data, const uint size)
	Initialize new array struct.
Array *	array_fromptr2 (DType dtype, uint ndim, void *data,...)
	Initialize new array struct.
void *	array_index (const Array a, uint idx)
	Index the array.
void *	array_index2 (const Array *a,...)
	Index the array.
void *	array_max (const Array *a)
	Get maximum element from array.
void *	array_min (const Array *a)
	Get minimum element from array.
Array *	array_new (DType dtype, uint ndim, const uint *dims)
	Initialize new array struct.
Array *	array_new2 (DType dtype, uint ndim,...)
	Initialize new array struct.
Array *	array_new_dummy (DType dtype, uint ndim,...)
	create array that is filled with values from 1 to n over all dimensions.
void	array_print (Array a, uint nel_per_dim, FILE out)
	print an array.
Array *	array_randunif (unsigned long seed, uint ndim,...)
	create array that is filled with random values from [0, ..., 1].
void	array_reverse (Array *a)
	Reverse order of elements in a (in-place).
int	array_scale (Array *a, double x)
	multiply all entries in array with x.
void	array_shuffle (Array *a, unsigned long seed)
	shuffle the entries of an array.
Array *	array_slice (const Array a, const char slicedesc)
	Extract sub-arrays from array.
void	array_typecast (Array *a, DType target_type)
	Array-typecast.

Function Documentation

void array_calc_colindex	(	ulong	offset,
		const uint *	size,
		uint	nsize,
		uint *	index
	)

calculate the column-major index-tuple given the offset from element 0.

It is assumed, that the data is in row-major format.

Parameters:

	offset
	size	the dimensions of the array
	nsize	number of dimensions
	index	(output) the index tuple

Definition at line 271 of file array.c.

void array_calc_rowindex	(	ulong	offset,
		const uint *	size,
		uint	nsize,
		uint *	index
	)

calculate the row-major index-tuple given the offset from element 0.

It is assumed, that the data is in row-major format.

Parameters:

	offset
	size	the dimensions of the array
	nsize	number of dimensions
	index	(output) the index tuple

Definition at line 244 of file array.c.

bool array_comparable	(	const Array *	a,
		const Array *	b
	)

Compare two array's dimensions and datatype.

Parameters:

a,b

the two arrays to be tested

Returns:: TRUE if both arrays have same dimensionality, FALSE otherwise.

Definition at line 344 of file array.c.

Array* array_concatenate	(	const Array *	a,
		const Array *	b,
		int	dim
	)

concatenate two arrays.

The two arrays must have the same number of elements in all dimensions except in the concatenated dimension.

Todo:: currently works only for 1D and 2D. implement nD if necessary.

Example:

	 [ 1 2     [ 7 8 
	   3 4       9 10
      5 6 ]    11 12] 

		=> [ 1 2
		     3 4
           5 6
           7 8
           9 10
			  11 12 ]

Parameters:

	a,b	the two arrays to concatenate (must be 1D/2D arrays of arbitrary type); if one of them is NULL, return a copy of the other one
	dim	the dimension along which they are to be concatenated (0-rows, 1-columns)

Returns:: the concatenation of a and b

Definition at line 167 of file array.c.

Array* array_convert_rowcolmajor	(	Array *	a,
		bool	alloc
	)

convert a row-major array to col-major.

This is a d-dimensional matrix-transpose.

Parameters:

	a	the row-major array
	alloc	if TRUE, allocate new memory, else overwrite a

Returns:: a new col-major array

Definition at line 297 of file array.c.

Array* array_copy	(	const Array *	in,
		bool	allocdata
	)

makes a copy of an array.

The flag allocdata determines, whether the memory is copied.

Parameters:

	in	input
	allocdata	allocate own data, or share data between arrays. Shared memory belongs to to the passed array.

Returns:: the copy

Definition at line 376 of file array.c.

int array_dimred ( Array * a )

Delete unnecessary dimensions (of size 1).

Dimensions of size 1 are removed from the size-array of the struct.

Parameters:

a

in-place reduction

Returns:: 0 on success, other on failure

Definition at line 395 of file array.c.

void array_dtype_to_double	(	double *	out,
		void *	mem,
		DType	dt
	)

cast memory of type dt in location mem to double.

Parameters:

	out	output double
	mem	the memory
	dt	the DType of mem

Definition at line 933 of file array.c.

void array_free ( Array * a )

free all memory associated with the array.

Definition at line 958 of file array.c.

Array* array_fromptr	(	DType	dtype,
		uint	ndim,
		void *	data,
		const uint *	size
	)

Initialize new array struct.

Memory for the data is not allocated but set to data.

Warning:: the array does NOT take over the responsibility for the memory. I.e. if you call array_free() it is NOT free'd. If you want this to happen, you need to set array->free_data to TRUE.

Parameters:

	dtype	the datatype of the array
	ndim	number of dimensions
	data	the data for the array
	...	the number of elements in each of the dimensions

Returns:: array

Definition at line 904 of file array.c.

Array* array_fromptr2	(	DType	dtype,
		uint	ndim,
		void *	data,
			...
	)

Initialize new array struct.

Memory for the data is not allocated but set to data.

Warning:: the array does NOT take over the responsibility for the memory. I.e. if you call array_free() it is NOT free'd. If you want this to happen, you need to set array->free_data to TRUE.

Parameters:

	dtype	the datatype of the array
	ndim	number of dimensions
	data	the data for the array
	...	the number of elements in each of the dimensions

Returns:: array

Definition at line 869 of file array.c.

void* array_index	(	const Array *	a,
		uint *	idx
	)

Index the array.

You need to provide as many arguments as there are dimensions in the array. A pointer to the corresponding memory in the array is returned. To use it you need to cast it:

     uint idx[3]={1,2,3};
     float a = *(float*)array_index( arr, idx );

Parameters:

	a	the array
	idx	array of size a->ndim giving the indices

Returns:: pointer to the memory at the specific location

Definition at line 638 of file array.c.

void* array_index2	(	const Array *	a,
			...
	)

Index the array.

You need to provide as many arguments as there are dimensions in the array. A pointer to the corresponding memory in the array is returned. To use it you need to cast it:

     float a = *(float*)array_index2( arr, 1, 2 );

Parameters:

	a	the array
	...	a->ndim integers

Returns:: pointer to the memory at the specific location

Definition at line 672 of file array.c.

void* array_max ( const Array * a )

Get maximum element from array.

You can easily find the index of this element by doing

     Array *a = get_array_from_somewhere();
     long idx = (array_max(a)-(a->data))/a->dtype_size;
     // if you need an index-tuple, you can do
     uint idxtuple[num_dimension];
     array_calc_rowindex( idx, a->size, a->ndim, idxtuple );

Note:: this function is a bit slow, as it converts everything to double before comparing. If you need it fast, you should consider writing a specialised function.

Parameters:

a

the array

Returns:: pointer to the maximum element

Definition at line 46 of file array.c.

void* array_min ( const Array * a )

Get minimum element from array.

You can easily find the index of this element by doing

     Array *a = get_array_from_somewhere();
     long idx = (array_min(a)-(a->data))/a->dtype_size;
     // if you need an index-tuple, you can do
     uint idxtuple[num_dimension];
     array_calc_rowindex( idx, a->size, a->ndim, idxtuple );

Note:: this function is a bit slow, as it converts everything to double before comparing. If you need it fast, you should consider writing a specialised function.

Parameters:

a

the array

Returns:: pointer to the minimum element

Definition at line 80 of file array.c.

Array* array_new	(	DType	dtype,
		uint	ndim,
		const uint *	dims
	)

Initialize new array struct.

Memory for the data is allocated and set to zero.

Parameters:

	dtype	the datatype of the array
	ndim	number of dimensions
	dims	number of elements in each of the dimensions

Returns:: array

Definition at line 699 of file array.c.

Array* array_new2	(	DType	dtype,
		uint	ndim,
			...
	)

Initialize new array struct.

Memory for the data is allocated and set to zero.

Parameters:

	dtype	the datatype of the array
	ndim	number of dimensions
	...	the number of elements in each of the dimensions

Returns:: array

Definition at line 737 of file array.c.

Array* array_new_dummy	(	DType	dtype,
		uint	ndim,
			...
	)

create array that is filled with values from 1 to n over all dimensions.

Mainly used for debugging stuff.

Parameters:

	dtype	the datatype of the array
	ndim	number of dimensions
	...	the number of elements in each of the dimensions

Returns:: array

Definition at line 830 of file array.c.

void array_print	(	Array *	a,
		uint	nel_per_dim,
		FILE *	out
	)

print an array.

Print to an output stream, nel_per_dim elements per dimension. Passing -1 for nel_per_dim prints everything.

Parameters:

	a	the array
	nel_per_dim	number of elements to print per dimension
	out	the output file/stream

Definition at line 603 of file array.c.

Array* array_randunif	(	unsigned long	seed,
		uint	ndim,
			...
	)

create array that is filled with random values from [0, ..., 1].

Mainly used for debugging stuff.

Parameters:

	seed	to use for the random numbers; if seed=0, the current time is used
	ndim	number of dimensions
	...	the number of elements in each of the dimensions

Returns:: array

Definition at line 767 of file array.c.

void array_reverse ( Array * a )

Reverse order of elements in a (in-place).

Dimensionality is not considered. I.e., the function loops over all elements such as they are stored in memory.

Parameters:

a

the array

Definition at line 323 of file array.c.

int array_scale	(	Array *	a,
		double	x
	)

multiply all entries in array with x.

Parameters:

	a	the input/output array
	x	the scalar to multiply a with

Definition at line 422 of file array.c.

void array_shuffle	(	Array *	a,
		unsigned long	seed
	)

shuffle the entries of an array.

Parameters:

	a	the array (arbitrary type and dimensionality)
	seed	if 0, use time(NULL), else the seed

Definition at line 805 of file array.c.

Array* array_slice	(	const Array *	a,
		const char *	slicedesc
	)

Extract sub-arrays from array.

This is a function for creating array slices from an existing array. I.e. you can extract sub-arrays similar to interpreted languages like python or MATLAB.

See Slicing Array Objects for the format of the slice string.

Parameters:

	a	the array
	slicedesc	the description of the slice as described in Slicing Array Objects

Returns:: a freshly allocated array containing the slice

Definition at line 522 of file array.c.

void array_typecast	(	Array *	a,
		DType	target_type
	)

Array-typecast.

Typecast the whole array.

Warning:

in case that sizeof(target_type)<sizeof(current_type), you lose precision
in case that sizeof(target_type)!=sizeof(current_type), it is slow because the whole data is copied

Parameters:

	a	the array
	target_type	the target type

Definition at line 108 of file array.c.

src/array.c File Reference

Functions

Function Documentation