matplotlib-users

[Matplotlib-users] Plot resolution of axes

[Miriam D. <md...@am...>]

Hi all,

I am working on a correlation chart with pyplot for a monitoring web 
tool. The plot is looking good, but only the strange resolution of axes 
disturbs the view.

In a simple correlation plot, e.g. I want to compare two temperature 
sensors, I expect a line who divides the picture in two halves with an 
angle of 45° (optimal correlation R²=1). That feels natural and you can 
see whether the both sensors correlate or not without a deeper look at 
the exact values. But pyplot shows me a chart, where the x-axis's tick 
interval is larger (108 pixel) than the y-axis's tick interval (77 
pixel). In attachment you can see my example.

How can I manipulate the axes that they show the same pixel resolution?

I hope I make my case clear. If more information is needed, please tell me.

Thank you very much in advance!

Miriam D.

Re: [Matplotlib-users] Plot resolution of axes

[Benjamin R. <ben...@ou...>]

On Mon, Mar 25, 2013 at 11:06 AM, Miriam Degginger <md...@am...> wrote:

> Hi all,
>
> I am working on a correlation chart with pyplot for a monitoring web tool.
> The plot is looking good, but only the strange resolution of axes disturbs
> the view.
>
> In a simple correlation plot, e.g. I want to compare two temperature
> sensors, I expect a line who divides the picture in two halves with an
> angle of 45° (optimal correlation R²=1). That feels natural and you can see
> whether the both sensors correlate or not without a deeper look at the
> exact values. But pyplot shows me a chart, where the x-axis's tick interval
> is larger (108 pixel) than the y-axis's tick interval (77 pixel). In
> attachment you can see my example.
>
> How can I manipulate the axes that they show the same pixel resolution?
>
> I hope I make my case clear. If more information is needed, please tell me.
>
> Thank you very much in advance!
>
> Miriam D.
>
>
Did you try:

ax.set_aspect('equal')

I don't know how you plotted your figure, so I don't know which matplotlib
objects you have at your disposal.  My above example would operate on the
Axes object returned by a call to add_subplot() or plt.subplot().

Cheers!
Ben Root

Re: [Matplotlib-users] Plot resolution of axes

[Jonathan S. <js...@cf...>]

Hi Miriam,

This case is a simple one for setting the axis ratios.  You want to set
the aspect ratio to equal:
gca().set_aspect('equal')
after making your plot

Jon

On Mon, 2013-03-25 at 16:06 +0100, Miriam Degginger wrote:
> Hi all,
> 
> I am working on a correlation chart with pyplot for a monitoring web 
> tool. The plot is looking good, but only the strange resolution of axes 
> disturbs the view.
> 
> In a simple correlation plot, e.g. I want to compare two temperature 
> sensors, I expect a line who divides the picture in two halves with an 
> angle of 45° (optimal correlation R²=1). That feels natural and you can 
> see whether the both sensors correlate or not without a deeper look at 
> the exact values. But pyplot shows me a chart, where the x-axis's tick 
> interval is larger (108 pixel) than the y-axis's tick interval (77 
> pixel). In attachment you can see my example.
> 
> How can I manipulate the axes that they show the same pixel resolution?
> 
> I hope I make my case clear. If more information is needed, please tell me.
> 
> Thank you very much in advance!
> 
> Miriam D.

-- 
______________________________________________________________
Jonathan D. Slavin              Harvard-Smithsonian CfA
js...@cf...         60 Garden Street, MS 83
phone: (617) 496-7981           Cambridge, MA 02138-1516
 cell: (781) 363-0035           USA
______________________________________________________________

Re: [Matplotlib-users] Plot resolution of axes

[Miriam D. <md...@am...>]

Hi Jon,

yes, this is what I am looking for. Now, the chart is like I've expected.

Thank you all! (...also for the quick response!)

Miriam D.


On 25/03/13 17:00, Jonathan Slavin wrote:
> Hi Miriam,
>
> This case is a simple one for setting the axis ratios.  You want to set
> the aspect ratio to equal:
> gca().set_aspect('equal')
> after making your plot
>
> Jon
>
> On Mon, 2013-03-25 at 16:06 +0100, Miriam Degginger wrote:
>> Hi all,
>>
>> I am working on a correlation chart with pyplot for a monitoring web
>> tool. The plot is looking good, but only the strange resolution of axes
>> disturbs the view.
>>
>> In a simple correlation plot, e.g. I want to compare two temperature
>> sensors, I expect a line who divides the picture in two halves with an
>> angle of 45° (optimal correlation R²=1). That feels natural and you can
>> see whether the both sensors correlate or not without a deeper look at
>> the exact values. But pyplot shows me a chart, where the x-axis's tick
>> interval is larger (108 pixel) than the y-axis's tick interval (77
>> pixel). In attachment you can see my example.
>>
>> How can I manipulate the axes that they show the same pixel resolution?
>>
>> I hope I make my case clear. If more information is needed, please tell me.
>>
>> Thank you very much in advance!
>>
>> Miriam D.