Hi Massimo,
thanks for you help!
i'm going ahead with little steps, i stored your code in a web2py controller :
mpl.py espone index, plot_interference
i tried it without modification, or just changing the return function to :
return dict(image=plot(data={'interferemce':[(x,x**2) for x in
range(100)]}))
in a web2py view i have :
###
{{extend 'layout.html'}}
<h1>Image generated with matplotlib</h1>
<img src="{{=d}}" alt="Red dot" />
###
the rendered page :
http://127.0.0.1:8000/welcome/mpl/plot_interference
looks like :
http://www.geofemengineering.it//img.png
i can see it is type() string, if i save it and add the .png extension i can
display the image
that' a big step ahead if compared with my old 'static' plot function ..
my problem (thanks for your patience) is that i'm still tying to understand
how to render that (string-image) in the web, and add a form to 'modify it'
(change input parameters) ?
thanks!
Massimo.
Il giorno May 13, 2012, alle ore 9:56 PM, Massimo Di Pierro ha scritto:
> # useful module
>
> import os, tempfile, random, cStringIO
>
>
>
> # setup a temporary working forlder
>
> os.environ['MPLCONfigureDIR'] = tempfile.mkdtemp()
>
>
>
> # main matplotlib modules
>
> from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
>
> from matplotlib.figure import Figure
>
>
>
> # optional for scatter plots
>
> from matplotlib.patches import Ellipse
>
>
> def plot(title='title',xlab='x',ylab='y',
>
> data={'xxx':[(0,0),(1,1),(1,2),(3,3)],
>
> 'yyy':[(0,0,.2),(2,1,0.2),(2,2,0.2),(3,3,0.2)]}):
>
>
>
> figure=Figure(frameon=False)
>
> axes=figure.add_subplot(111)
>
> if title: axes.set_title(title)
>
> if xlab: axes.set_xlabel(xlab)
>
> if ylab: axes.set_ylabel(ylab)
>
> keys=sorted(data) # sort data series by name
>
> for key in keys: # for each data series
>
> stream = data[key]
>
> (x,y)=([],[]) # make empty list x and empty list
> y
>
> yerr = [] # ... and empty list yerr
> (optional)
>
> for point in stream: # for each point in series
>
> x.append(point[0]) # append X coordinate to x
>
> y.append(point[1]) # append Y coordinate to y
>
> if len(point)==3: # if dY, append dY to yerr
>
> yerr.append(point[2])
>
> ell=axes.plot(x, y, linewidth="2") # plot y vs x
>
> if len(yerr)==len(x): # if error bars, display them
>
> axes.errorbar(x, y, yerr=yerr, fmt='o', linewidth="1")
>
>
>
> canvas=FigureCanvas(figure)
>
> stream=cStringIO.StringIO()
>
> canvas.print_png(stream)
>
> return stream.getvalue()
>
>
>
>
> def plot_interference():
>
> return plot(data={'interferemce':[(x,x**2) for x in range(100)]})
>
>
>
>
>
>
> On Sunday, 13 May 2012 13:02:37 UTC-5, epifanio wrote:
>
> i'm looking for a solution, to start to write a web-app to generate graph
> using matplotlib
> the graph needs to be generated using some inputs parameters coming from the
> page itself.
>
> right now i'm rewriting the app from scratch .. but i'm stuck on how to
> integrate a query button to the python code ..
>
> essentially what i need to start is :
>
> a page with a line-edit input box + Jquery widget (a simple button, will be
> enough to learn more)
>
> then connect the button to execute a generic python code that will use as
> input the text in the line-edit
> .. the generic python code will process the text received as input and return
> the results on the same page where the line-edit and the button are.
>
> i hope my description gives you an idea of what i was looking for
>
> Many thanks for any help!
>
>
> Massimo.
>
>
> Il giorno May 11, 2012, alle ore 10:49 AM, Massimo Di Stefano ha scritto:
>
>>
>> Hi All,
>>
>> i'm tring to learn web2py, thanks for the wonderful book and for the really
>> nice tutorial!
>> i'm a bit 'stuck' on how to perform a simple task (i guess it is simple)
>> because of my ignorance.
>>
>> .. i'm bring to update dynamic a graph-chart (generated with matplotlib)
>> using a form to pass the input the draw-function.
>>
>>
>> what i have is a controller :
>>
>> # template_example.py that 'espone' a function 'variables' , it will
>> display an image generated by matplotlib using the 'stem_plot' function (in
>> the same .py file)
>>
>>
>> # import a lib that generate the data from the url gived as input
>> from ecoopclimate import Climate
>> #import some matplotlib methodsm numpy ...
>> from pylab import stem, setp, grid, savefig, show, gca, subplot,
>> subplots_adjust
>> import matplotlib as mpl
>> import matplotlib.pyplot as plt
>> import datetime as dt
>> import numpy as np
>> # plot function
>> def stem_plot(data, name):
>> data[np.isnan(data)]=0
>> fig = plt.figure()
>> ax = fig.add_subplot(211)
>> mindate = int(data[0][0])
>> maxdate = int(data[0][-1])
>> date2_1 = dt.datetime(mindate, 1, 1)
>> date2_2 = dt.datetime(maxdate, 1, 1)
>> delta2 = dt.timedelta(days=365)
>> dates2 = mpl.dates.drange(date2_1, date2_2, delta2)
>>
>> dateFmt = mpl.dates.DateFormatter('%Y')
>> ax.xaxis.set_major_formatter(dateFmt)
>> fig.autofmt_xdate(bottom=0.1)
>> x_p = dates2[np.where(data[1]>=0)[0]]
>> y_p = data[1][np.where(data[1]>=0)[0]]
>> x_n = dates2[np.where(data[1]<0)[0]]
>> y_n = data[1][np.where(data[1]<0)[0]]
>>
>> markerline, stemlines, baseline = stem(x_p, y_p, 'r-')
>> setp(markerline, 'markerfacecolor', 'b')
>> setp(baseline, 'color', 'r', 'linewidth', 2)
>> setp(stemlines, 'linewidth', 1)
>> markerline, stemlines, baseline = stem(x_n, y_n, 'b-')
>> setp(markerline, 'markerfacecolor', 'b')
>> setp(baseline, 'color', 'r', 'linewidth', 2)
>> setp(stemlines, 'linewidth', 1)
>> grid()
>> setp(gca(), 'xlabel', 'Year', 'ylabel', name)
>> fig = '/Users/epifanio/web2py/applications/welcome/static/'+name+'.png'
>> dateFmt = mpl.dates.DateFormatter('%Y')
>> savefig(fig)
>> return fig
>> #show()
>>
>> # function connected to the view : variables.html
>> def variables():
>> nao_url =
>> 'https://climatedataguide.ucar.edu/sites/default/files/cas_data_files/asphilli/nao_station_djfm.txt'
>> clm = Climate()
>> NAO = clm.nao(nao_url, 'nao.txt')
>> image = stem_plot(NAO['nao'], 'nao')
>> return dict(d=URL('static', 'nao.png'))
>>
>>
>> the view template_example/variables.html is :
>>
>> {{extend 'layout.html'}}
>> <h1>Image generated with matplotlib</h1>
>>
>> <img src="{{=d}}" alt="Red dot" />
>>
>>
>> As you can see from the code in stem_plot it takes as input : 'data' and
>> 'name'
>> i'm hardcoding the var inside the function 'variables'
>>
>> i need to modify that code adding a 'form' in the view that will take 2
>> string as input
>>
>> nao_url =
>> 'https://climatedataguide.ucar.edu/sites/default/files/cas_data_files/asphilli/nao_station_djfm.txt'
>> image_name = 'imagename'
>>
>> and pass this input to the main function that generate the graph.
>> Have you any hints on how to do that ?
>> i'd like to have the form in the same page where the image is displayed
>> so that i can update the image every time i'll resubmit the form.
>> i'm a beginner, an example that does something like that will be really
>> helpful :)
>> Many many Thanks for your help!
>> Massimo.
>>
>>
>>
>>
>>
>
