# Want to remove unnecessary message

Manipulate[
ParametricPlot[{t, t}, {t, 0, s}],
{s, 0, 1, 0.1}]


This code is working in Mathematica, but generates messages (ParametricPlot::plld). I tried Quiet, but result was still the same.

I looked at Off, but not understand how to use it.

• The reason for the message is that ParametricPlot[{0,0}] doesn't work. If you do something like Manipulate[ParametricPlot[{t, t}, {t, 0, s}], {s, 0.001, 1, 0.1}] instead (note the s initial value to 0.001) it will stop issuing the message. – Carl Lange Jan 24 '19 at 17:31
• The bigger question here is why does Quiet[ParametricPlot[{t, t}, {t, 0, s}]]; issue a message? – Jason B. Jan 24 '19 at 17:38
• I think it's because it evaluates inside the Quiet, comes back unevaluated, then reevaluates upon return. Try f /; (Print; 1/0) = Null; Quiet[f]. – Chip Hurst Jan 24 '19 at 21:26
• Possible duplicate: mathematica.stackexchange.com/questions/120868/… – Michael E2 Jan 24 '19 at 22:52
• Perhaps this might be a helpful example: Manipulate[ ParametricPlot[{Sin[2 t], Cos[3 t]}, {t, 0, 2 Pi}, Mesh -> {{s}}, MeshStyle -> Red, MeshShading -> {ColorData, None}, PlotRange -> 1], {s, 0, 2 Pi}] – Michael E2 Jan 25 '19 at 2:46

The endpoints for t are 0 and s, so when s is 0, ParametricPlot tries to plot t from 0 to 0 and produces this message.
You can solve the problem by setting the lower bound of s to a value strictly larger than 0:
Manipulate[ParametricPlot[{t,t},{t,0,s}],{s,0.1,1,0.1}]]