"""Make bar chart from a bunch of columns from a simple data file
Each *column* is a bar graph

bar <filename>

file:  x_1  y1_1  y2_1  y3_1  ...
       x_2  y1_2  y2_2  y3_2  ...
       :
       x_n  y1_n  y2_n  y3_n  ...
Also recognizes structured comments #t, #x, #y, #s
"""
from pylab import *	# required for matplotlib
import sys              # argv[]
import numpy            # mean, std

y=array([])
name=''                 # filename to save plot in
f=open(sys.argv[1], "rU")	# readonly, unformatted?
xlim = (0,)                # default: no X-limits given


def readfile(filename):
    global labels,y,name,nlab,ylab, nrow, ncol, nlabel
    labels = []                     # the data column labels
    y = array([])                   # the 2D array of numbers read in
    print "Reading",filename
    f=open(filename, "rU")	    # readonly, unformatted?

    for line in f:
        line = line.replace("\n","")        # strip trailing '\n'
        #print line  #debug
        if line=="": continue       #ignore blank lines
        line = line.replace("\\n", "\n")    # replace user 2-char \n with real \n
        
        if line[:3]=="#t ":
            title(line[3:])
            continue
        if line[:3]=="#n ":         # only used for 'n' choice of X values
            nlab = line[3:]
            continue
        if line[:3]=="#x ":         # backward compatibility: becomes label[0]
            labels.insert(0, line[3:])
            continue
        if line[:3]=="#y ":         # append another column label to the list
            labels.append(line[3:])
            continue
        if line[:3]=="#s ":
            name = line[3:].strip()
            continue
        if line[:1]=="#":  continue # ignore comments

        # must be data: strip trailing comments and remove commas
        s = line.find("#")
        if s >= 0:  line = line[:s]
        words = line.replace("{"," ").replace("}"," ")   # remove C punctuation
        words = words.replace("/"," ")
        words = words.replace(","," ").split()

        # remove columns that aren't numbers
        for i in range(len(words)-1, -1, -1):   # oddly, goes from (len-1) to 0
            if "+-.0123456789".find(words[i][0]) < 0:  words.pop(i)
        
        new = [float(s) for s in words]    # the new row of data
        new = array(new)
        #print len(y),y,new
        if len(y) == 0:
            y = new
            ncol = len(new)
        else: y = vstack( (y, new) )
    f.close()
    print "shape(y) = ",shape(y)
    nrow,ncol = shape(y)
    nlabel = size(labels)
    print "   nrow=", nrow,"ncol=",ncol
#end readfile()

readfile(sys.argv[1])
# all the data are read into 2D array y[,].

#for i in range(nrow):
#    print i, "%17.12f" % numpy.average(y[i,:]), \
#             "%17.12f" % numpy.std(y[i,:], ddof=1)

# Now plot 'em
# each plot string specifies the column, and color
nbar = size(sys.argv[2:])
plotn = 0
width = 0
for i in sys.argv[2:]:
    if i[:3] == "fi=":
        readfile(i[3:])
        #ys = 1; yo = 0      # scale and offset
        continue

    if i[:3]=="ti=":
        title(i[3:])
        continue

    if i[:3]=="sa=":
        name = i[3:]        # save filename
        continue

    if i[:3]=="xl=":        # X label
        xlabel(i[3:])
        continue

    if i[:3]=="yl=":        # Y label
        ylabel(i[3:])
        continue
    
    if i[:3]=="xa=":        # X-axis limits
        words=i[3:].split(":")
        xlim=(float(words[0]), float(words[1]) )
        #axis(xmin=float(words[0]), xmax=float(words[1]) )
        continue
    
    if i[:3]=="ya=":        # Y-axis limits
        words=i[3:].split(":")
        axis(ymin=float(words[0]), ymax=float(words[1]) )
        continue

    
    if i[0]=='n':
        x = range(1,nrow+1) # 1..n
        xlabel(nlab)        # special label
    else:
        col = int(i[0], 36) # radix 36 allows >9 columns
        x = y[:,col]
        if col < nlabel: xlabel(labels[col])

    if width == 0: width = 0.8*(x[1]-x[0]) # total width of all bars in a column

    col = int(i[1], 36)     # radix 36 allows >9 columns
    plotn += 1
    left = width/nbar*(plotn-1)
    color = i[2:]
    if col < size(labels): label = labels[col]
    else: label = ""
    print i,col,left,color,label
    bar(x+left, y[:,col], width/nbar, align='center', color=color, \
        label=label)

if len(xlim) > 1: axis(xmin=xlim[0], xmax=xlim[1])
if len(labels) > 1:  legend(loc=0)
grid(True)
if name != '':  savefig(name)
show()