diff options
Diffstat (limited to 'doc/ref/api-compound.texi')
-rw-r--r-- | doc/ref/api-compound.texi | 34 |
1 files changed, 15 insertions, 19 deletions
diff --git a/doc/ref/api-compound.texi b/doc/ref/api-compound.texi index 34a832fa1..ef4869cc1 100644 --- a/doc/ref/api-compound.texi +++ b/doc/ref/api-compound.texi @@ -1795,14 +1795,12 @@ of @var{idxlist} is shorter than @math{n}, then return the shared For example: -@example @lisp (array-from #2((a b) (c d)) 0) @result{} #(a b) (array-from #2((a b) (c d)) 1) @result{} #(c d) (array-from #2((a b) (c d)) 1 1) @result{} d (array-from #2((a b) (c d))) @result{} #2((a b) (c d)) @end lisp -@end example @code{(apply array-from array indices)} is equivalent to @@ -1827,7 +1825,6 @@ write into. Compare: -@example @lisp (array-from #2((a b) (c d)) 1 1) @result{} d (array-from* #2((a b) (c d)) 1) @result{} #0(d) @@ -1836,7 +1833,6 @@ Compare: a @result{} #2((a a) (a b)). (array-fill! (array-from a 1 1) 'b) @result{} error: not an array @end lisp -@end example @code{(apply array-from* array indices)} is equivalent to @@ -1863,12 +1859,19 @@ This function returns the modified @var{array}. For example: -@example @lisp (array-amend! (make-array 'a 2 2) b 1 1) @result{} #2((a a) (a b)) (array-amend! (make-array 'a 2 2) #(x y) 1) @result{} #2((a a) (x y)) @end lisp -@end example + +Note that @code{array-amend!} will expect elements, not arrays, when the +destination has rank 0. One can work around this using +@code{array-from*} instead. + +@lisp +(array-amend! (make-array 'a 2 2) #0(b) 1 1) @result{} #2((a a) (a #0(b))) +(let ((a (make-array 'a 2 2))) (array-copy! #0(b) (array-from* a 1 1)) a) @result{} #2((a a) (a b)) +@end lisp @code{(apply array-amend! array x indices)} is equivalent to @@ -1886,10 +1889,10 @@ The name `amend' comes from the J language. @deffn {Scheme Procedure} array-for-each-cell frame-rank op x @dots{} @deffnx {C Function} scm_array_for_each_cell (array, frame_rank, op, xlist) -Each @var{x} must be an array of rank @math{n_x} ≥ @var{frame-rank}, and +Each @var{x} must be an array of rank ≥ @var{frame-rank}, and the first @var{frame-rank} dimensions of each @var{x} must all be the same. @var{array-for-each-cell} calls @var{op} with each set of -(@math{n_x} - @var{frame-rank})-cells from @var{x}, in unspecified order. +(rank(@var{x}) - @var{frame-rank})-cells from @var{x}, in unspecified order. @var{array-for-each-cell} allows you to loop over cells of any rank without having to carry an index list or construct slices manually. The @@ -1898,26 +1901,20 @@ to write to them. This function returns an unspecified value. -For example: +For example, to sort the rows of rank-2 array @code{a}: -@example -Sort the rows of rank-2 array @code{a}: @lisp (array-for-each-cell 1 (lambda (x) (sort! x <)) a) @end lisp -@end example -@example -Let @code{a} be a rank-2 array where each row is a 2-vector @math{x, -y}. Compute the norms of these vectors and store them in rank-1 array -@code{b}: +As another example, let @code{a} be a rank-2 array where each row is a 2-vector @math{(x,y)}. +Let's compute the arguments of these vectors and store them in rank-1 array @code{b}. @lisp (array-for-each-cell 1 (lambda (a b) - (array-set! b (hypot (array-ref a 0) (array-ref a 1)))) + (array-set! b (atan (array-ref a 1) (array-ref a 0)))) a b) @end lisp -@end example @code{(apply array-for-each-cell frame-rank op x)} is functionally equivalent to @@ -1933,7 +1930,6 @@ equivalent to (lambda i (apply op (map (lambda (x) (apply array-from* x i)) x))))) @end lisp -The name `amend' comes from the J language. @end deffn |