Hi Zelphir,

> ...
> Now, using Guile-CV, on my relatively slow laptop (i5-2450M CPU @ 2.50GHz × 4 - 6GB
> RAM):

> 	scheme@(guile-user)> ,use (cv)

> 	scheme@(guile-user)> (im-make 1000 1000 1)
> 	$5 = (1000 1000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
> 0.0 # …)))

> 	scheme@(guile-user)> ,time (im-transpose $5)
> 	$6 = (1000 1000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
> 0.0 # …))) ;; 0.342220s real time, 0.367022s run time.  0.040217s spent in GC.
> 
> 	scheme@(guile-user)> (im-make 1000 10000 1)
> 	$7 = (1000 10000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
> 0.0 # …)))
> 
> 	scheme@(guile-user)> ,time (im-transpose $7)
> 	$8 = (10000 1000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
> > 0.0 # …))) ;; 3.186683s real time, 3.374562s run time.  0.303187s spent in GC.
> 
> But I see that im-transpose still is pure scheme code, I'll write the low level
> operation in C and post back ...

I moved the im-transpose core functionality to libguile-cv, and now I get these
results (roughly 22x faster):

	scheme@(guile-user)> ,use (cv)
	scheme@(guile-user)> (im-make 1000 1000 1)
	$2 = (1000 1000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 # …)))
	scheme@(guile-user)> ,time (im-transpose $2)
	$3 = (1000 1000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 # …)))
	;; 0.027255s real time, 0.035129s run time.  0.014336s spent in GC.

	scheme@(guile-user)> (im-make 1000 10000 1)
	$4 = (1000 10000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 # …)))
	scheme@(guile-user)> ,time (im-transpose $4)
	$5 = (10000 1000 1 (#f32(0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 # …)))
	;; 0.141708s real time, 0.147565s run time.  0.024564s spent in GC.

Note that if yo plan to 'play with' Guile-CV (and expect the above last figures):

	(a) you have to install form the source and check the devel branch (didn't
	merge to master yet and do not plan to release soon);

	(b) make sure you read the 'Configuring Guile for Guile-CV' before you even
	start ...

Cheers,
David