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Hi, I am looking for a way to assign the value of a TeX macro to an MP variable. However, this only works the first time, then the value is not updated any longer. Example: \startMPdefinitions size = \somesize ; \stopMPdefinitions \startuseMPgraphic{alpha} fill unitcircle scaled size; \stopuseMPgraphic \starttext \def\somesize{1cm} \useMPgraphic{alpha} %% diameter = 1cm \def\somesize{2cm} \useMPgraphic{alpha} %% diameter = 1cm \stoptext I looked into \setupMPvariables, but I couldn't manage to assign them to an MP variable. The setups key from \defineMPinstance seems to to the job, but it's TeX, not MetaPost. What comes to mind is a \processMPbuffer before every MPgraphic: \startbuffer[foo] size := \somesize ; \stopbuffer \startuseMPgraphic{alpha} fill unitcircle scaled size; \stopuseMPgraphic \starttext \def\somesize{1cm} \processMPbuffer[foo] \useMPgraphic{alpha} %% diameter = 1cm \def\somesize{2cm} \processMPbuffer[foo] \useMPgraphic{alpha} %% diameter = 2cm \stoptext Is there a better way? Marco