Perform simple reformatting of the ticks in a plot?

Questions
1

I often deal with graphs involving large dollar amounts over time. Mathematica will generally format Y-axis ticks as scientific numbers {1.0x10^6, 1.2x10^6 . . . etc.}.

So for example,

mydata = EventSeries@
  Table[{DatePlus[DateObject[{2010, 1, 1}], {x, "Month"}], 
    10^6 RandomReal[{1, 2}]}, {x, 0, 20}];

myplot = DateListPlot[mydata] (* produces a Y-axis in scientific notation, which is not what I want *)

I’m happy to let Mathematica pick where the ticks go, but I want to change the formatting to {$1.0MM, $1.2MM . . . etc.}.

Is there an elegant way to do this?

2

Manually specify the ticks:

mydata=EventSeries@Table[{DatePlus[DateObject[{2010,1,1}],{x,"Month"}],10^6 RandomReal[{1,2}]},{x,0,20}];
rightticks=leftticks = {# 10^6,"$ "<>ToString[NumberForm[#,{\[Infinity],1}]]<>"MM"}&/@Range[1,2,0.1];
rightticks[[All,2]]="";
myplot=DateListPlot[mydata,FrameTicks->{{leftticks,rightticks},{Automatic,Automatic}}]

ScreenShot2017-02-15at18.57.12.png
ScreenShot2017-02-15at18.57.12.png738×432 32.6 KB

Using FindDivisions you could automate the position of the ticks. Which is also what internally is used by the various plot functionalities…

3

I generate a lot of these graphs with varying Y-axes so I would greatly prefer not to have to set the upper and lower bounds by hand. Is there some mechanism that lets Mathematica pick the placement but lets me pick the formatting?

4

You can intercept the automatically generated ticks and then tweak them, for example with a replacement rule. Something like this:

myPlot = Plot[Sin[x], {x, 0, Pi}]
tks = Ticks /. AbsoluteOptions[myPlot, Ticks];
Show[myPlot, 
 Ticks -> {tks[[1]] /. {x_Real, tk_Real, rest___} :> {x, 
      Rationalize[tk/Pi, Pi/10000] Pi, rest}, tks[[2]]}]
5

Currently only semi-manually, like Gianluca proposed…

6

This doesn’t work with DateListPlots.

7

Hmm, AbsoluteOptions gives useless result with DateListPlot. A workaround is to get the ticks from a ListPlot and to feed them to DateListPlot:

data = {{{2017, 1, 1}, 1}, {{2017, 2, 1}, 2}};
nonDatePlot = ListPlot[data[[All, -1]]];
tks = Ticks /. AbsoluteOptions[nonDatePlot];
modifiedTks = 
  tks[[2]] /. {x_Real, tk_Real, rest___} :> {x, 
     Rationalize[tk/Pi, Pi/10000] Pi, rest};
DateListPlot[data, 
 FrameTicks -> {{modifiedTks, Automatic}, Automatic}]
8

Hi, I am interested in this solution too. I would like to use human readable numeric values on my charts, not in scientific notation. I could not find how to do that. I am using Mathematica 12.1.1
Thanks!