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plotting - Animated Vector plot


I'm trying to make an animation of a time-varying 2D vector field. However, I'm got a difficulty in that Mathematica normalises the length of the vectors with each call to VectorPlot.


A (very simple) example:


myField = {Cos[2 π t], 0};

Animate[
        VectorPlot[myField /. t -> TT, {x, -1, 1}, {y, -1, 1}],
        {TT, 0, 1}]


Expected result: The arrows grow and shrink in time


The actual result: The arrows remain the same size, but flick direction


Is there some way to fix the length of the arrows relative to the field value?



Answer



As @Ox4A4D mentioned in the comment, you could use the option VectorScale to set the length of vectors, here is an example code:


myField = {Cos[2 \[Pi] t], 0};
Animate[VectorPlot[myField /. t -> TT, {x, -1, 1}, {y, -1, 1}, 
          VectorScale -> Abs[0.05 Cos[2 Pi TT]]], {TT, 0, 1}]

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