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This page describes breaking API changes between diagrams 1.1 and 1.2, along with explanations of how to migrate to the new 1.2 API.

Attributes using Measure

Many distances are now specified using values of type Measure. See the user manual for full details. The most noticeable effects of this change in porting diagrams code to 1.2 will be type errors on uses of attribute functions like lw, dashing, and fontSize.

  • To simply retain the existing behavior, replace lw with lwG, dashing with dashingG, and fontSize with fontSizeL.
  • In many cases, you can simply remove calls to lw, since the default behavior is much more sensible. You can also use the named line weights provided in Diagrams.TwoD.Attributes: none, ultraThin, veryThin, thin, medium, thick, veryThick, or ultraThick. For example, replace lw 0 with lw none, and replace (say) lw 0.2 with lw veryThick (though note that the relationship between the number used previously and the proper choice of line weight depends on the context, because the old semantics was not very sensible).

Removal of freeze

The freeze function has been removed. Most users probably were not using it; if you were, you have several options for replacing it, depending on how you were using it:

  • If you were just using it to get some lines to scale along with a diagram, use a Local line width (e.g. ... # lw (Local 2) or ... # lwL 2).
  • The above will not work if you were doing non-uniform scaling and really care that the lines should come out looking squished and stretched. In that case, use functions in Diagrams.TwoD.Offset to create a path corresponding to the stroked line, and then fill and transform it normally.


The size of arrow heads and tails is now specified in terms of length instead of the radius of their circumcircle. In addition, the lengths are specified using Measure. For convenience, aliases tiny, verySmall, small, normal, large, veryLarge, and huge have been provided. For example,

... & headSize .~ 0.7

might be replaced with

... & headLength .~ large

Gaps at the ends of arrows are also specified using Measure R2. Also, the gap traversal has been replaced by gaps for consistency in naming, though gap is still provided for backwards compatibility. For example, replace

... & gap .~ 1


... & gaps .~ Local 1



These changes will not affect most users, but are listed here for completeness.

  • The avgScale function has been moved from Diagrams.TwoD.Transform to Diagrams.Core.Transform.
  • Most 2D attributes have been moved from Diagrams.Attributes to Diagrams.TwoD.Attributes.
  • The Angle definition and related functions have moved to a separate module, Diagrams.Angle.