Looking at the metapost examples in the Wiki it appears that a block symbol can be defined or redefined which allows the size of the block to be changed. Does this apply to each instance of a block or is it a global definition. How do you specify the size of the block when you place it in the drawing?

  code metapost
   def p_blocks_UIS (expr pos,theta,sc,al)=
    symbolsize:=1.0u; %Factor*u; Factor=size of the blocks
    U:=(.5u,.5u);
    T:=identity aligned al rotated theta scaled sc shifted pos;
    pickup PenC;
    thdraw (.0symbolsize,.0symbolsize)--(1.0symbolsize,-.5symbolsize)--(0.0symbolsize,-1.5symbolsize)--(-1.0symbolsize,-1.0symbolsize)--cycle;
    thdraw (.5symbolsize,-.25symbolsize)--(1.0symbolsize,.5symbolsize)--(0.0symbolsize,1.5symbolsize)--(-0.5symbolsize,.5symbolsize);
    thdraw (.0symbolsize,.0symbolsize)--(.0symbolsize,.5symbolsize)--(-1.5symbolsize,.5symbolsize)--(-1.5symbolsize,-0.5symbolsize)--(-0.5symbolsize,-0.5symbolsize);
   enddef;
  endcode



Dave Clucas
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