matplotlib-users

[Matplotlib-users] mathtext and postscript backend

[Humufr <hu...@ya...>]

       Hello,

I have a problem to obtain a good ps file (with mathematical symbol) 
with matplotlib. That's work very good with a png file but not with a 
postscript.

I tried to define the TTFPATH and AFMPATH but that change nothing. I 
think that I miss one configuration somewhere but I can't arrive to find 
what...

Thank you for this soft, I just begin to use but it's seems very 
interesting

    Nicolas

Re: [Matplotlib-users] mathtext and postscript backend

[John H. <jdh...@ac...>]

>>>>> "Humufr" == Humufr  <hu...@ya...> writes:

    Humufr>        Hello, I have a problem to obtain a good ps file
    Humufr> (with mathematical symbol) with matplotlib. That's work
    Humufr> very good with a png file but not with a postscript.

    Humufr> I tried to define the TTFPATH and AFMPATH but that change
    Humufr> nothing. I think that I miss one configuration somewhere
    Humufr> but I can't arrive to find what...

    Humufr> Thank you for this soft, I just begin to use but it's
    Humufr> seems very interesting

I haven't yet added mathtext to the postscript backend, though I will
as soon as I get the time.  See the mathtext documentation at
http://matplotlib.sf.net/matplotlib.mathtext.html for the latest
information about mathtext, which backends it works on, etc...

mathtext is designed around the BaKoMa truetype fonts.  There are also
postscript versions of these fonts.  Paul Barrett has been working on
unifying the interface between AFM (postscript) and truetype fonts,
but we're not there yet.  When this is done, it will be easier to
rewrite mathtext to work with either kind of font.  Another
possibility is to modify the postscript backend to use postscript
level 3, which supports truetype fonts.  This would be very nice
because it would improve compatibility between the postscript, image
and GUI backends.

Another thing that needs to be done is to add image support to the
postscript backend (draw_image).  This shouldn't be too hard.  The
matplotlib freetype module ft2font has a method to get the font raster
as a bitmap, which could be placed on the PS canvas with draw_image.
This wouldn't be an ideal solution because it's not scalable, but it
would be a fairly easy temporary solution.

Volunteers welcome!
JDH

[Matplotlib-users] connecting data points...

[Peter G. <pgr...@ge...>]

Hi everyone:

I was wondering whether it is possible to tell matplotlib how/when to 
connect data points. Consider this simple script:

from matplotlib.matlab import *
 
figure(1)
t = [0,1,2,3,4,5,105,106,107]
s = [1,4,5,3,9,11,-5,-8,3]
plot(t, s, antialiased=False)
 
grid(True)
show()


There are no data points between t=5 and t=105. By default the points 
(5,11) and (105,-5) are connected, but I would like to tell matplotlib 
NOT to do so. In my case I would like to pass the plot function a 
variable telling it what to do. So for example would have:

plot(t, s, max_delta=40)

This would mean that the points are only to be connected if the 
difference between the adjacent t values is less than 40.  

In my case this is relevant because sometimes there are "holes" in my 
data, and connecting the points makes the plots look very messy.

Would anyone find something like this useful? Would it be difficult to 
implement?

Thanks.
Peter

Re: [Matplotlib-users] connecting data points...

[John H. <jdh...@ac...>]

>>>>> "Peter" == Peter Groszkowski <pgr...@ge...> writes:

    Peter> Hi everyone: I was wondering whether it is possible to tell
    Peter> matplotlib how/when to connect data points. Consider this
    Peter> simple script:

    Peter> from matplotlib.matlab import * figure(1) t =
    Peter> [0,1,2,3,4,5,105,106,107] s = [1,4,5,3,9,11,-5,-8,3]
    Peter> plot(t, s, antialiased=False) grid(True) show()


    Peter> There are no data points between t=5 and t=105. By default
    Peter> the points (5,11) and (105,-5) are connected, but I would
    Peter> like to tell matplotlib NOT to do so. In my case I would
    Peter> like to pass the plot function a variable telling it what
    Peter> to do. So for example would have:

    Peter> plot(t, s, max_delta=40)

    Peter> This would mean that the points are only to be connected if
    Peter> the difference between the adjacent t values is less than
    Peter> 40.  In my case this is relevant because sometimes there
    Peter> are "holes" in my data, and connecting the points makes the
    Peter> plots look very messy.

    Peter> Would anyone find something like this useful? Would it be
    Peter> difficult to implement?

Certainly not difficult, and probably useful enough to put in the
standard distro.  Eg, in a stock market trading example, you would
have lots of quotes, minute by minute, punctuated by long intervals
overnight where the market is closed.  If you set maxdelta
appropriately, you could draw connected lines only within trading
days.

Here is a sample implementation

from matplotlib.matlab import *
def segplot(x, y, fmt, maxdelta, **kwargs):
    """
    Plot x versus y, breaking the plot at any point where x[i] -
    x[i-1] > maxdelta. kwargs are passed on to plot
    """
    x = asarray(x)
    y = asarray(y)
    d = diff(x)
    lines = []
    ind = nonzero(greater(d, maxdelta))
    ind = ind+1
    if not len(ind):
        lines.extend( plot(x,y,fmt,**kwargs) ) 
    else:
        allind = [0]
        allind.extend(ind)
        allind.append(len(x))
        for i1,i2 in zip(allind[:-1], allind[1:]):
            lines.extend( plot(x[i1:i2], y[i1:i2], fmt, **kwargs) )
    return lines

t = [0,1,2,3,4,5,105,106,107,187, 200, 212, 300, 320]
s = [1,4,5,3,9,11,-5,-8,3,12, 15, 12, -1, 3]
segplot(t, s, 'b-o', 40, antialiased=False)
grid(True)
show()

I'm inclined not to make this part of plot, since plot processes a
variable number of arguments it makes it a little difficult.
Certainly doable, but I'm hesitant to put too much on plot because it
might become unwieldy.  But a new function, like segment plot, would
be easy enough to include.

Any suggestions for a name, or additional functionality?

JDH

Re: [Matplotlib-users] connecting data points...

[Peter G. <pgr...@ge...>]

John Hunter wrote:

[snip]

>Here is a sample implementation
>
>from matplotlib.matlab import *
>def segplot(x, y, fmt, maxdelta, **kwargs):
>    """
>    Plot x versus y, breaking the plot at any point where x[i] -
>    x[i-1] > maxdelta. kwargs are passed on to plot
>    """
>    x = asarray(x)
>    y = asarray(y)
>    d = diff(x)
>    lines = []
>    ind = nonzero(greater(d, maxdelta))
>    ind = ind+1
>    if not len(ind):
>        lines.extend( plot(x,y,fmt,**kwargs) ) 
>    else:
>        allind = [0]
>        allind.extend(ind)
>        allind.append(len(x))
>        for i1,i2 in zip(allind[:-1], allind[1:]):
>            lines.extend( plot(x[i1:i2], y[i1:i2], fmt, **kwargs) )
>    return lines
>
>t = [0,1,2,3,4,5,105,106,107,187, 200, 212, 300, 320]
>s = [1,4,5,3,9,11,-5,-8,3,12, 15, 12, -1, 3]
>segplot(t, s, 'b-o', 40, antialiased=False)
>grid(True)
>show()
>
>I'm inclined not to make this part of plot, since plot processes a
>variable number of arguments it makes it a little difficult.
>Certainly doable, but I'm hesitant to put too much on plot because it
>might become unwieldy.  But a new function, like segment plot, would
>be easy enough to include.
>
>Any suggestions for a name, or additional functionality?
>  
>
Thanks for the quick solution. I think the name is just fine.

Best,

-- 
Peter Groszkowski         Gemini Observatory
Tel: +1 808 974-2509      670 N. A'ohoku Place
Fax: +1 808 935-9235      Hilo, Hawai'i 96720, USA

Re: [Matplotlib-users] connecting data points...

[Vincent B. <bo...@cl...>]

Hi everybody.

Related to this discussion, here is something else that could be very 
useful for me :

Let's say

t =[0,5,15,18]
s = [1,9,-5]

I'd like to plot a curve f(x) using s and t in a way that :
	- f(x)=1 for x in [0,5]
	- f(x)=9 for x in [5,15]
	- f(x)=-51 for x in [5,18]

Is there already a simple way to do that using Matplotlib, and if not, would it be possible to add it?

Thanx
Vincent



John Hunter wrote:

>>>>>>"Peter" == Peter Groszkowski <pgr...@ge...> writes:
>>>>>>
>
>    Peter> Hi everyone: I was wondering whether it is possible to tell
>    Peter> matplotlib how/when to connect data points. Consider this
>    Peter> simple script:
>
>    Peter> from matplotlib.matlab import * figure(1) t =
>    Peter> [0,1,2,3,4,5,105,106,107] s = [1,4,5,3,9,11,-5,-8,3]
>    Peter> plot(t, s, antialiased=False) grid(True) show()
>
>
>    Peter> There are no data points between t=5 and t=105. By default
>    Peter> the points (5,11) and (105,-5) are connected, but I would
>    Peter> like to tell matplotlib NOT to do so. In my case I would
>    Peter> like to pass the plot function a variable telling it what
>    Peter> to do. So for example would have:
>
>    Peter> plot(t, s, max_delta=40)
>
>    Peter> This would mean that the points are only to be connected if
>    Peter> the difference between the adjacent t values is less than
>    Peter> 40.  In my case this is relevant because sometimes there
>    Peter> are "holes" in my data, and connecting the points makes the
>    Peter> plots look very messy.
>
>    Peter> Would anyone find something like this useful? Would it be
>    Peter> difficult to implement?
>
>Certainly not difficult, and probably useful enough to put in the
>standard distro.  Eg, in a stock market trading example, you would
>have lots of quotes, minute by minute, punctuated by long intervals
>overnight where the market is closed.  If you set maxdelta
>appropriately, you could draw connected lines only within trading
>days.
>
>Here is a sample implementation
>
>from matplotlib.matlab import *
>def segplot(x, y, fmt, maxdelta, **kwargs):
>    """
>    Plot x versus y, breaking the plot at any point where x[i] -
>    x[i-1] > maxdelta. kwargs are passed on to plot
>    """
>    x = asarray(x)
>    y = asarray(y)
>    d = diff(x)
>    lines = []
>    ind = nonzero(greater(d, maxdelta))
>    ind = ind+1
>    if not len(ind):
>        lines.extend( plot(x,y,fmt,**kwargs) ) 
>    else:
>        allind = [0]
>        allind.extend(ind)
>        allind.append(len(x))
>        for i1,i2 in zip(allind[:-1], allind[1:]):
>            lines.extend( plot(x[i1:i2], y[i1:i2], fmt, **kwargs) )
>    return lines
>
>t = [0,1,2,3,4,5,105,106,107,187, 200, 212, 300, 320]
>s = [1,4,5,3,9,11,-5,-8,3,12, 15, 12, -1, 3]
>segplot(t, s, 'b-o', 40, antialiased=False)
>grid(True)
>show()
>
>I'm inclined not to make this part of plot, since plot processes a
>variable number of arguments it makes it a little difficult.
>Certainly doable, but I'm hesitant to put too much on plot because it
>might become unwieldy.  But a new function, like segment plot, would
>be easy enough to include.
>
>Any suggestions for a name, or additional functionality?
>
>JDH
>
>
>-------------------------------------------------------
>This SF.Net email is sponsored by: IBM Linux Tutorials
>Free Linux tutorial presented by Daniel Robbins, President and CEO of
>GenToo technologies. Learn everything from fundamentals to system
>administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click
>_______________________________________________
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>
>

Re: [Matplotlib-users] connecting data points...

[Greg W. <gr...@th...>]

I assume that's a typo and is supposed to be "f(x)=-5 for [15,18].  Is
this what you want?

plot([0,5,5,15,15,18],
     [1,1,9, 9,-5,-5])


On Wed, 2004-04-07 at 05:12, Vincent BOYER wrote:
> Hi everybody.
> 
> Related to this discussion, here is something else that could be very 
> useful for me :
> 
> Let's say
> 
> t =[0,5,15,18]
> s = [1,9,-5]
> 
> I'd like to plot a curve f(x) using s and t in a way that :
> 	- f(x)=1 for x in [0,5]
> 	- f(x)=9 for x in [5,15]
> 	- f(x)=-51 for x in [5,18]
> 
> Is there already a simple way to do that using Matplotlib, and if not, would it be possible to add it?
> 
> Thanx
> Vincent
> 
> 
> 
> John Hunter wrote:
> 
> >>>>>>"Peter" == Peter Groszkowski <pgr...@ge...> writes:
> >>>>>>
> >
> >    Peter> Hi everyone: I was wondering whether it is possible to tell
> >    Peter> matplotlib how/when to connect data points. Consider this
> >    Peter> simple script:
> >
> >    Peter> from matplotlib.matlab import * figure(1) t =
> >    Peter> [0,1,2,3,4,5,105,106,107] s = [1,4,5,3,9,11,-5,-8,3]
> >    Peter> plot(t, s, antialiased=False) grid(True) show()
> >
> >
> >    Peter> There are no data points between t=5 and t=105. By default
> >    Peter> the points (5,11) and (105,-5) are connected, but I would
> >    Peter> like to tell matplotlib NOT to do so. In my case I would
> >    Peter> like to pass the plot function a variable telling it what
> >    Peter> to do. So for example would have:
> >
> >    Peter> plot(t, s, max_delta=40)
> >
> >    Peter> This would mean that the points are only to be connected if
> >    Peter> the difference between the adjacent t values is less than
> >    Peter> 40.  In my case this is relevant because sometimes there
> >    Peter> are "holes" in my data, and connecting the points makes the
> >    Peter> plots look very messy.
> >
> >    Peter> Would anyone find something like this useful? Would it be
> >    Peter> difficult to implement?
> >
> >Certainly not difficult, and probably useful enough to put in the
> >standard distro.  Eg, in a stock market trading example, you would
> >have lots of quotes, minute by minute, punctuated by long intervals
> >overnight where the market is closed.  If you set maxdelta
> >appropriately, you could draw connected lines only within trading
> >days.
> >
> >Here is a sample implementation
> >
> >from matplotlib.matlab import *
> >def segplot(x, y, fmt, maxdelta, **kwargs):
> >    """
> >    Plot x versus y, breaking the plot at any point where x[i] -
> >    x[i-1] > maxdelta. kwargs are passed on to plot
> >    """
> >    x = asarray(x)
> >    y = asarray(y)
> >    d = diff(x)
> >    lines = []
> >    ind = nonzero(greater(d, maxdelta))
> >    ind = ind+1
> >    if not len(ind):
> >        lines.extend( plot(x,y,fmt,**kwargs) ) 
> >    else:
> >        allind = [0]
> >        allind.extend(ind)
> >        allind.append(len(x))
> >        for i1,i2 in zip(allind[:-1], allind[1:]):
> >            lines.extend( plot(x[i1:i2], y[i1:i2], fmt, **kwargs) )
> >    return lines
> >
> >t = [0,1,2,3,4,5,105,106,107,187, 200, 212, 300, 320]
> >s = [1,4,5,3,9,11,-5,-8,3,12, 15, 12, -1, 3]
> >segplot(t, s, 'b-o', 40, antialiased=False)
> >grid(True)
> >show()
> >
> >I'm inclined not to make this part of plot, since plot processes a
> >variable number of arguments it makes it a little difficult.
> >Certainly doable, but I'm hesitant to put too much on plot because it
> >might become unwieldy.  But a new function, like segment plot, would
> >be easy enough to include.
> >
> >Any suggestions for a name, or additional functionality?
> >
> >JDH
> >
> >
> >-------------------------------------------------------
> >This SF.Net email is sponsored by: IBM Linux Tutorials
> >Free Linux tutorial presented by Daniel Robbins, President and CEO of
> >GenToo technologies. Learn everything from fundamentals to system
> >administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click
> >_______________________________________________
> >Matplotlib-users mailing list
> >Mat...@li...
> >https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> >
> >
> 
> 
> 
> 
> -------------------------------------------------------
> This SF.Net email is sponsored by: IBM Linux Tutorials
> Free Linux tutorial presented by Daniel Robbins, President and CEO of
> GenToo technologies. Learn everything from fundamentals to system
> administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click
> _______________________________________________
> Matplotlib-users mailing list
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-- 
Greg Whittier <gr...@th...>