.. _api-sankey_demo_old:

api example code: sankey_demo_old.py
====================================



.. plot:: /media/TOSHI/temp/numpy_scipy_matplotlib/matplotlib/matplotlib-1.1.1~rc2/doc/mpl_examples/api/sankey_demo_old.py

::

    #!/usr/bin/env python
    
    __author__ = "Yannick Copin <ycopin@ipnl.in2p3.fr>"
    __version__ = "Time-stamp: <10/02/2010 16:49 ycopin@lyopc548.in2p3.fr>"
    
    import numpy as N
    
    def sankey(ax,
               outputs=[100.], outlabels=None,
               inputs=[100.], inlabels='',
               dx=40, dy=10, outangle=45, w=3, inangle=30, offset=2, **kwargs):
        """Draw a Sankey diagram.
    
    outputs: array of outputs, should sum up to 100%
    outlabels: output labels (same length as outputs),
    or None (use default labels) or '' (no labels)
    inputs and inlabels: similar for inputs
    dx: horizontal elongation
    dy: vertical elongation
    outangle: output arrow angle [deg]
    w: output arrow shoulder
    inangle: input dip angle
    offset: text offset
    **kwargs: propagated to Patch (e.g. fill=False)
    
    Return (patch,[intexts,outtexts])."""
    
        import matplotlib.patches as mpatches
        from matplotlib.path import Path
    
        outs = N.absolute(outputs)
        outsigns = N.sign(outputs)
        outsigns[-1] = 0 # Last output
    
        ins = N.absolute(inputs)
        insigns = N.sign(inputs)
        insigns[0] = 0 # First input
    
        assert sum(outs)==100, "Outputs don't sum up to 100%"
        assert sum(ins)==100, "Inputs don't sum up to 100%"
    
        def add_output(path, loss, sign=1):
            h = (loss/2+w)*N.tan(outangle/180.*N.pi) # Arrow tip height
            move,(x,y) = path[-1] # Use last point as reference
            if sign==0: # Final loss (horizontal)
                path.extend([(Path.LINETO,[x+dx,y]),
                             (Path.LINETO,[x+dx,y+w]),
                             (Path.LINETO,[x+dx+h,y-loss/2]), # Tip
                             (Path.LINETO,[x+dx,y-loss-w]),
                             (Path.LINETO,[x+dx,y-loss])])
                outtips.append((sign,path[-3][1]))
            else: # Intermediate loss (vertical)
                path.extend([(Path.CURVE4,[x+dx/2,y]),
                             (Path.CURVE4,[x+dx,y]),
                             (Path.CURVE4,[x+dx,y+sign*dy]),
                             (Path.LINETO,[x+dx-w,y+sign*dy]),
                             (Path.LINETO,[x+dx+loss/2,y+sign*(dy+h)]), # Tip
                             (Path.LINETO,[x+dx+loss+w,y+sign*dy]),
                             (Path.LINETO,[x+dx+loss,y+sign*dy]),
                             (Path.CURVE3,[x+dx+loss,y-sign*loss]),
                             (Path.CURVE3,[x+dx/2+loss,y-sign*loss])])
                outtips.append((sign,path[-5][1]))
    
        def add_input(path, gain, sign=1):
            h = (gain/2)*N.tan(inangle/180.*N.pi) # Dip depth
            move,(x,y) = path[-1] # Use last point as reference
            if sign==0: # First gain (horizontal)
                path.extend([(Path.LINETO,[x-dx,y]),
                             (Path.LINETO,[x-dx+h,y+gain/2]), # Dip
                             (Path.LINETO,[x-dx,y+gain])])
                xd,yd = path[-2][1] # Dip position
                indips.append((sign,[xd-h,yd]))
            else: # Intermediate gain (vertical)
                path.extend([(Path.CURVE4,[x-dx/2,y]),
                             (Path.CURVE4,[x-dx,y]),
                             (Path.CURVE4,[x-dx,y+sign*dy]),
                             (Path.LINETO,[x-dx-gain/2,y+sign*(dy-h)]), # Dip
                             (Path.LINETO,[x-dx-gain,y+sign*dy]),
                             (Path.CURVE3,[x-dx-gain,y-sign*gain]),
                             (Path.CURVE3,[x-dx/2-gain,y-sign*gain])])
                xd,yd = path[-4][1] # Dip position
                indips.append((sign,[xd,yd+sign*h]))
    
        outtips = [] # Output arrow tip dir. and positions
        urpath = [(Path.MOVETO,[0,100])] # 1st point of upper right path
        lrpath = [(Path.LINETO,[0,0])] # 1st point of lower right path
        for loss,sign in zip(outs,outsigns):
            add_output(sign>=0 and urpath or lrpath, loss, sign=sign)
    
        indips = [] # Input arrow tip dir. and positions
        llpath = [(Path.LINETO,[0,0])] # 1st point of lower left path
        ulpath = [(Path.MOVETO,[0,100])] # 1st point of upper left path
        for gain,sign in zip(ins,insigns)[::-1]:
            add_input(sign<=0 and llpath or ulpath, gain, sign=sign)
    
        def revert(path):
            """A path is not just revertable by path[::-1] because of Bezier
    curves."""
            rpath = []
            nextmove = Path.LINETO
            for move,pos in path[::-1]:
                rpath.append((nextmove,pos))
                nextmove = move
            return rpath
    
        # Concatenate subpathes in correct order
        path = urpath + revert(lrpath) + llpath + revert(ulpath)
    
        codes,verts = zip(*path)
        verts = N.array(verts)
    
        # Path patch
        path = Path(verts,codes)
        patch = mpatches.PathPatch(path, **kwargs)
        ax.add_patch(patch)
    
        if False: # DEBUG
            print "urpath", urpath
            print "lrpath", revert(lrpath)
            print "llpath", llpath
            print "ulpath", revert(ulpath)
    
            xs,ys = zip(*verts)
            ax.plot(xs,ys,'go-')
    
        # Labels
    
        def set_labels(labels,values):
            """Set or check labels according to values."""
            if labels=='': # No labels
                return labels
            elif labels is None: # Default labels
                return [ '%2d%%' % val for val in values ]
            else:
                assert len(labels)==len(values)
                return labels
    
        def put_labels(labels,positions,output=True):
            """Put labels to positions."""
            texts = []
            lbls = output and labels or labels[::-1]
            for i,label in enumerate(lbls):
                s,(x,y) = positions[i] # Label direction and position
                if s==0:
                    t = ax.text(x+offset,y,label,
                                ha=output and 'left' or 'right', va='center')
                elif s>0:
                    t = ax.text(x,y+offset,label, ha='center', va='bottom')
                else:
                    t = ax.text(x,y-offset,label, ha='center', va='top')
                texts.append(t)
            return texts
    
        outlabels = set_labels(outlabels, outs)
        outtexts = put_labels(outlabels, outtips, output=True)
    
        inlabels = set_labels(inlabels, ins)
        intexts = put_labels(inlabels, indips, output=False)
    
        # Axes management
        ax.set_xlim(verts[:,0].min()-dx, verts[:,0].max()+dx)
        ax.set_ylim(verts[:,1].min()-dy, verts[:,1].max()+dy)
        ax.set_aspect('equal', adjustable='datalim')
    
        return patch,[intexts,outtexts]
    
    if __name__=='__main__':
    
        import matplotlib.pyplot as P
    
        outputs = [10.,-20.,5.,15.,-10.,40.]
        outlabels = ['First','Second','Third','Fourth','Fifth','Hurray!']
        outlabels = [ s+'\n%d%%' % abs(l) for l,s in zip(outputs,outlabels) ]
    
        inputs = [60.,-25.,15.]
    
        fig = P.figure()
        ax = fig.add_subplot(1,1,1, xticks=[],yticks=[],
                             title="Sankey diagram"
                             )
    
        patch,(intexts,outtexts) = sankey(ax, outputs=outputs, outlabels=outlabels,
                                          inputs=inputs, inlabels=None,
                                          fc='g', alpha=0.2)
        outtexts[1].set_color('r')
        outtexts[-1].set_fontweight('bold')
    
        P.show()
    
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)