mjhjmtu

I have a large set of pictures, and I want to apply predefined settings to each using the optional argument of the includegraphics macro from the graphicx package.

I would like to define the settings once at the top of the file (like defsettingswidth=textwidth, angle=90), and then apply them to all of my images so that I can modify all of the settings from one place.

If I run the following code block, it gives me the versions of the error "Package xkeyval Error: 'width=textwidth, angle=90' undefined in families 'Gin'", which seems to be because it's interpreting my entire group of settings as a single key input.

documentclassarticle
usepackagegraphix
begindocument

 defsettingsAwidth=textwidth, angle=90
 defsettingsBpage=1, scale=.1
 defsettingsCangle=90, scale=.5

 beginfigure
 includegraphics[settingsA]filename1.png
 labelfig:oneofonehundred
 endfigure

 beginfigure
 includegraphics[settingsB]filename2.pdf
 labelfig:twoofonehundred
 endfigure

 beginfigure
 includegraphics[settingsC]filename3.jpg
 labelfig:threeofonehundred
 endfigure

 enddocument

What is the technique to modify this settings string so that it is interpreted correctly? How do I pass an optional argument that is interpreted as a set of arguments instead of one string?

Thanks in advance!

Just define new keys:

documentclassarticle
usepackagegraphicx

makeatletter
define@keyGinsettingsAsetkeysGinwidth=textwidth, angle=90
define@keyGinsettingsBsetkeysGinpage=1, scale=.1
define@keyGinsettingsCsetkeysGinangle=-90, scale=.5
makeatother

begindocument

includegraphics[settingsA]example-image-a

includegraphics[settingsB]example-image-b

includegraphics[settingsC]example-image-c

enddocument

A bit of explanation. The graphicx package relies on keyval provided key-value syntax and reserves Gin (Graphic inclusion) as the family name of the keys for includegraphics. A new key is simply added by

define@keyGin<name>[<default value>]<code>

The includegraphics[<options>]file command will do

setkeysGin<options>

and every known key will be processed. The default empty value given for settingsA and so on is so that you can simply type settingsA without =something.

One could even improve it; say that in settingsC you want to be able to vary the angle; with

define@keyGinsettingsC[-90]setkeysGinangle=#1, scale=.5

you can specify settingsC for the angle to be -90 or

settingsC=45

for the angle to be 45.

Caveat Be sure not to define an already existing key: define@key would silently overwrite it.

Make your own include graphics command. Something like the following:

newcommandmyincludegraphics[2]%%
 expandafterincludegraphicsexpandafter[#1]#2

The problem with your code is that in the construction

includegraphics[settingsA]filehandle

The unexpanded settingsA is getting passed to the key parser where it will fail to match any keys. By using the above command, you can write something like,

myincludegraphicssettingsAfilehandle

By using expandafter, settingsA will be expanded by the time includegraphics has a chance to pass the optional arguments to its parser.