Save GIF with Animation package {R} - r

Question

I would like to save a set of maps as gif with the animation package. I produce these maps for different years through a function I created. The function works.
However, I don't manage to save the output as a gif. This is what I coded:
i<- 1
saveGIF(
for(i in 1955:1957)
multiplePlots(i),
interval = .65,
movie.name = "test.gif",
img.name="test",
convert = "convert"
)
The error is the following (copy-pasted from the console, I hope it helps):
Executing:
""C:\Program Files\ImageMagick-6.9.3-Q16\convert.exe" -loop 0 -delay 65 test1.png test2.png test3.png "test.gif""
convert.exe: unable to load module `C:\Program Files\ImageMagick-6.9.3-Q16\modules\coders\IM_MOD_RL_PNG_.dll': Le module spécifié est introuvable.
# error/module.c/OpenModule/1300.
convert.exe: no decode delegate for this image format `PNG' # error/constitute.c/ReadImage/501.
convert.exe: unable to load module `C:\Program Files\ImageMagick-6.9.3-Q16\modules\coders\IM_MOD_RL_PNG_.dll': Le module spécifié est introuvable.
# error/module.c/OpenModule/1300.
convert.exe: no decode delegate for this image format `PNG' # error/constitute.c/ReadImage/501.
convert.exe: unable to load module `C:\Program Files\ImageMagick-6.9.3-Q16\modules\coders\IM_MOD_RL_PNG_.dll': Le module spécifié est introuvable.
# error/module.c/OpenModule/1300.
convert.exe: no decode delegate for this image format `PNG' # error/constitute.c/ReadImage/501.
convert.exe: no images defined `test.gif' # error/convert.c/ConvertImageCommand/3252.
an error occurred in the conversion... see Notes in ?im.convert
[1] FALSE
Warning messages:
1: running command 'C:\Windows\system32\cmd.exe /c ""C:\Program Files\ImageMagick-6.9.3-Q16\convert.exe" -loop 0 -delay 65 test1.png test2.png test3.png "test.gif""' had status 1
2: In cmd.fun(convert) :
'""C:\Program Files\ImageMagick-6.9.3-Q16\convert.exe" -loop 0 -delay 65 test1.png test2.png test3.png "test.gif""' execution failed with error code 1
3: running command '""C:\Program Files\ImageMagick-6.9.3-Q16\convert.exe" -loop 0 -delay 65 test1.png test2.png test3.png "test.gif""' had status 127
4: In normalizePath(path.expand(path), winslash, mustWork) :
path[1]="test.gif": Le fichier spécifié est introuvable
In case you are wondering, I have ImageMagick installed.
Many thanks.