diff linear_regression.py @ 0:ffcdde989859 draft

Uploaded

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/linear_regression.py	Tue Jul 29 06:30:45 2014 -0400
@@ -0,0 +1,158 @@
+#!/usr/bin/env python
+
+import sys, string
+import rpy2.robjects as robjects
+import rpy2.rlike.container as rlc
+from rpy2.robjects.packages import importr
+r = robjects.r
+grdevices = importr('grDevices')
+#  from rpy import *
+import numpy
+
+
+def stop_err(msg):
+    sys.stderr.write(msg)
+    sys.exit()
+
+infile = sys.argv[1]
+y_col = int(sys.argv[2])-1
+x_cols = sys.argv[3].split(',')
+outfile = sys.argv[4]
+outfile2 = sys.argv[5]
+
+print "Predictor columns: %s; Response column: %d" %(x_cols,y_col+1)
+fout = open(outfile,'w')
+elems = []
+for i, line in enumerate( file ( infile )):
+    line = line.rstrip('\r\n')
+    if len( line )>0 and not line.startswith( '#' ):
+        elems = line.split( '\t' )
+        break 
+    if i == 30:
+        break # Hopefully we'll never get here...
+
+if len( elems )<1:
+    stop_err( "The data in your input dataset is either missing or not formatted properly." )
+
+y_vals = []
+x_vals = []
+
+for k,col in enumerate(x_cols):
+    x_cols[k] = int(col)-1
+    # x_vals.append([])
+
+NA = 'NA'
+for ind,line in enumerate( file( infile )):
+    if line and not line.startswith( '#' ):
+        try:
+            fields = line.split("\t")
+            try:
+                yval = float(fields[y_col])
+            except:
+                yval = r('NA')
+            y_vals.append(yval)
+            for k,col in enumerate(x_cols):
+                try:
+                    xval = float(fields[col])
+                except:
+                    xval = r('NA')
+                # x_vals[k].append(xval)
+                x_vals.append(xval)
+        except:
+            pass
+# x_vals1 = numpy.asarray(x_vals).transpose()
+# dat= r.list(x=array(x_vals1), y=y_vals)
+fv = robjects.FloatVector(x_vals)
+m = r['matrix'](fv, ncol=len(x_cols),byrow=True)
+# ensure order for generating formula
+od = rlc.OrdDict([('y',robjects.FloatVector(y_vals)),('x',m)])
+dat = robjects.DataFrame(od)
+# convert dat.names: ["y","x.1","x.2"] to formula string: 'y ~ x.1 + x.2'
+formula = ' + '.join(dat.names).replace('+','~',1)
+
+#set_default_mode(NO_CONVERSION)
+try:
+    #linear_model = r.lm(r("y ~ x"), data = r.na_exclude(dat))
+    linear_model = r.lm(formula,  data =  r['na.exclude'](dat))
+except RException, rex:
+    stop_err("Error performing linear regression on the input data.\nEither the response column or one of the predictor columns contain only non-numeric or invalid values.")
+#set_default_mode(BASIC_CONVERSION)
+
+#coeffs=linear_model.as_py()['coefficients']
+#yintercept= coeffs['(Intercept)']
+coeffs=linear_model.rx2('coefficients')
+yintercept= coeffs.rx2('(Intercept)')[0]
+summary = r.summary(linear_model)
+
+#co = summary.get('coefficients', 'NA')
+co = summary.rx2("coefficients")
+
+"""
+if len(co) != len(x_vals)+1:
+    stop_err("Stopped performing linear regression on the input data, since one of the predictor columns contains only non-numeric or invalid values.")
+"""
+#print >>fout, "p-value (Y-intercept)\t%s" %(co[0][3])
+print >>fout, "p-value (Y-intercept)\t%s" %(co.rx(1,4)[0])
+
+if len(x_vals) == 1:    #Simple linear  regression case with 1 predictor variable
+    try:
+        #slope = coeffs['x']
+        slope = r.round(float(coeffs.rx2('x')[0]), digits=10)
+    except:
+        slope = 'NA'
+    try:
+        #pval = co[1][3]
+        pval = r.round(float(co.rx(2,4)[0]), digits=10)
+    except:
+        pval = 'NA'
+    print >>fout, "Slope (c%d)\t%s" %(x_cols[0]+1,slope)
+    print >>fout, "p-value (c%d)\t%s" %(x_cols[0]+1,pval)
+else:    #Multiple regression case with >1 predictors
+    ind=1
+    #while ind < len(coeffs.keys()):
+    while ind < len(coeffs.names):
+        # print >>fout, "Slope (c%d)\t%s" %(x_cols[ind-1]+1,coeffs['x'+str(ind)])
+        print >>fout, "Slope (c%d)\t%s" %(x_cols[ind-1]+1,coeffs.rx2(coeffs.names[ind])[0])
+        try:
+            #pval = co[ind][3]
+            pval = r.round(float(co.rx(ind+1,4)[0]), digits=10)
+        except:
+            pval = 'NA'
+        print >>fout, "p-value (c%d)\t%s" %(x_cols[ind-1]+1,pval)
+        ind+=1
+
+rsq = summary.rx2('r.squared')[0]
+adjrsq = summary.rx2('adj.r.squared')[0]
+fstat = summary.rx2('fstatistic').rx2('value')[0]
+sigma = summary.rx2('sigma')[0]
+
+try:
+    rsq = r.round(float(rsq), digits=5)
+    adjrsq = r.round(float(adjrsq), digits=5)
+    fval = r.round(fstat['value'], digits=5)
+    fstat['value'] = str(fval)
+    sigma = r.round(float(sigma), digits=10)
+except:
+    pass
+
+print >>fout, "R-squared\t%s" %(rsq)
+print >>fout, "Adjusted R-squared\t%s" %(adjrsq)
+print >>fout, "F-statistic\t%s" %(fstat)
+print >>fout, "Sigma\t%s" %(sigma)
+
+r.pdf( outfile2, 8, 8 )
+if len(x_vals) == 1:    #Simple linear  regression case with 1 predictor variable
+    sub_title =  "Slope = %s; Y-int = %s" %(slope,yintercept)
+    try:
+        r.plot(x=x_vals[0], y=y_vals, xlab="X", ylab="Y", sub=sub_title, main="Scatterplot with regression")
+        r.abline(a=yintercept, b=slope, col="red")
+    except:
+        pass
+else:
+    r.pairs(dat, main="Scatterplot Matrix", col="blue")
+try:
+    r.plot(linear_model)
+except:
+    pass
+#r.dev_off()
+grdevices.dev_off()