Thread: [Matplotlib-users] positions and scientific notations of ticks

Hi,

I'm plotting figures for a series of data set and I want to keep the 
looking consistent with each other. Currently I'm using MaxNLocator and 
ScalarFormatter but still,

1. Is there a way to limit the minimum number of ticks for MaxNLocator? 
Currently, if I set nbins=5, the number of ticks varies from 2 to 5. The 
variation is too large for me. I tried FixedLocator but then I lost the 
ability to set "ylim" (or "xlim") automatically.

2. About the scientific notation of ScalarFormatter, can I fix the 
number of decimal places? Currently, the notation will be "2x10^-5" in 
some figures, while "2.50x10^-5" in other figures. I need all tick 
labels to have the same number of decimal places.

I've searched the online documents for hours but cann't find the 
answer... any ideas?

Thanks!

-- 
Sincerely yours
Xing

On 05/04/2012 07:13 PM, stecue wrote:
> Hi,
>
> I'm plotting figures for a series of data set and I want to keep the
> looking consistent with each other. Currently I'm using MaxNLocator and
> ScalarFormatter but still,
>
> 1. Is there a way to limit the minimum number of ticks for MaxNLocator?
> Currently, if I set nbins=5, the number of ticks varies from 2 to 5. The
> variation is too large for me. I tried FixedLocator but then I lost the
> ability to set "ylim" (or "xlim") automatically.

You cannot limit it directly to a given number, but you can make it 
stick closer to the max number by giving it more latitude in selecting 
what can be a tick.  You do this via the "steps" kwarg.
>
> 2. About the scientific notation of ScalarFormatter, can I fix the
> number of decimal places? Currently, the notation will be "2x10^-5" in
> some figures, while "2.50x10^-5" in other figures. I need all tick
> labels to have the same number of decimal places.

It sounds like you need to use a FormatStrFormatter instead of a 
ScalarFormatter.

Eric

>
> I've searched the online documents for hours but cann't find the
> answer... any ideas?
>
> Thanks!
>

Dear All,

I've figured out that I can use LinearLocator and set ylim manually to 
fix the number of ticks. But I still don't know to set the display 
precision of the scientific notation. Currently I can only work around 
this by choosing proper limits and number of ticks manually. Is there 
anyway to fore the display precision (i.e, "3.33x10^-6" instead of 
"3.33333333333 x10^-6") ?

Thanks very much!

Sincerely yours
Xing


On 05/05/2012 01:13 AM, stecue wrote:
> Hi,
>
> I'm plotting figures for a series of data set and I want to keep the 
> looking consistent with each other. Currently I'm using MaxNLocator 
> and ScalarFormatter but still,
>
> 1. Is there a way to limit the minimum number of ticks for 
> MaxNLocator? Currently, if I set nbins=5, the number of ticks varies 
> from 2 to 5. The variation is too large for me. I tried FixedLocator 
> but then I lost the ability to set "ylim" (or "xlim") automatically.
>
> 2. About the scientific notation of ScalarFormatter, can I fix the 
> number of decimal places? Currently, the notation will be "2x10^-5" in 
> some figures, while "2.50x10^-5" in other figures. I need all tick 
> labels to have the same number of decimal places.
>
> I've searched the online documents for hours but cann't find the 
> answer... any ideas?
>
> Thanks!
>