# Make the y-axis of a plot be in terms of an arbitrary parameter instead of a number?

Sorry if the title is wordy. Basically what I am asking would probably be easier if I just use an example.

Say I wanted to plot f(x) = Asin(x) and have the graph come up with the sine function, and then the tics on the y axis be like half integer multiples of A. What I have been doing for my homework assignments is just plotting f(x)=sin(x) and then turning off the ticks and manually adding my ticks. It would be really cool if mathematica could do this for me.

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I think what you ended up doing is perhaps the best way... it isn't all that complicated either. – R. M. Nov 13 '13 at 20:44
What do you mean by manually? Are you using a custom tick specification as in this documentation example?: Plot[Cos[x], {x, 0, 10}, Ticks -> {{{Pi, 180 \[Degree], {0, .5}, Red}, {2 Pi, 360 \[Degree], {.5, 0}, Thick}, {3 Pi, 540 \[Degree], {0, .5}, Directive[Red, Dashed]}}, {-1, 1}}] – Mr.Wizard Nov 13 '13 at 20:48

See Ticks in the documentation:

Plot[Sin[x], {x, 0, 2 Pi},
Ticks -> {Automatic, Table[{y, Row[{y, " A"}]}, {y, -1, 1, 1/2}]}]


Unless you meant A to be a numeric value:

With[{A = Sqrt[2]},
Plot[A Sin[x], {x, 0, 2 Pi},
Ticks -> {Automatic, Range[-1, 1, 1/2] A}]
]


(OK, A = Sqrt[2] is a bit random. :)

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