Plotting Graphs + Bestfit lines

[arslanburney]

Hello. Ive got two functions here. Somehow the program does not go in
to the second function wehn i call it. The bestfit function. Could
some1 help me identify the problem. Heres the code:
import Gnuplot

def bestfit(uinput) :

if not isinstance(uinp ut, list):
return False

else:
sigmax = sigmay = sigmaxy = sigmaxwhl = sigmaxsq = 0

for i in range(len(uinpu t)):

n = len(uinput)

sigmax = uinput[i][0] + sigmax
sigmay = uinput[i][1] + sigmay
sigmaxy = uinput[i][0] * uinput [i][1] + sigmaxy
sigmaxwhl = sigmax * sigmax
sigmaxsq = uinput[i][0] * uinput[i][0] + sigmaxsq
sigmaxsigmay = sigmax * sigmay

num = sigmaxsigmay - (n * sigmaxy)
den = sigmaxwhl - (n* sigmaxsq)

num2 = (sigmax * sigmaxy) - (sigmay * sigmaxsq)
gradient = num / den

intercept = num2 / den

m = gradient
c = intercept

p = Gnuplot.Gnuplot ()
p.plot ('%f * x+%f'%(m,c))

return p

def plot(original, expected, actual):
if not isinstance(orig inal, list):
return False

else:

gp = Gnuplot.Gnuplot ()
gp('set data style lines')

# Make the plot items
plot1 = Gnuplot.PlotIte ms.Data(origina l, title="Original ")
plot2 = Gnuplot.PlotIte ms.Data(expecte d, title="Expected ")
plot3 = Gnuplot.PlotIte ms.Data(actual, title="Acutal")
gp.plot(plot1, plot2, plot3)
bestfit(expecte d)
bestfit(actual)

return gp
-------

import Combine #The name of my file...

gp = Combine.plot( [(2,3), (4,8), (5,9), (6,2)], [(1,7), (3,3), (4,5),
(5,6)], [(1,3), (3,10), (4,8), (7,9) ] )
raw_input()

[Peter Otten]

ar**********@gm ail.com wrote:

Hello. Ive got two functions here. Somehow the program does not go in
to the second function wehn i call it. The bestfit function. Could
some1 help me identify the problem. Heres the code:

Same problem as before, you have to keep the Gnuplot instance alive if you
want to see the graph.

Note that instead of

for i in range(len(uinpu t)):
sigmaxy = uinput[i][0] * uinput[i][1] + sigmaxy

you could write

for x, y in uinput:
sigmaxy += x * y

High time to take a look into a good Python tutorial...

# --- combine.py ---
import Gnuplot

def bestfit(uinput) :
sigmax = sigmay = sigmaxy = sigmaxwhl = sigmaxsq = 0

for i in range(len(uinpu t)):

n = len(uinput)

sigmax = uinput[i][0] + sigmax
sigmay = uinput[i][1] + sigmay
sigmaxy = uinput[i][0] * uinput [i][1] + sigmaxy
sigmaxwhl = sigmax * sigmax
sigmaxsq = uinput[i][0] * uinput[i][0] + sigmaxsq
sigmaxsigmay = sigmax * sigmay

num = sigmaxsigmay - (n * sigmaxy)
den = sigmaxwhl - (n* sigmaxsq)

num2 = (sigmax * sigmaxy) - (sigmay * sigmaxsq)
gradient = num / den

intercept = num2 / den

m = gradient
c = intercept

p = Gnuplot.Gnuplot ()
p.plot ('%f * x+%f'%(m,c))

return p

def plot(original, expected, actual):
gp = Gnuplot.Gnuplot ()
gp('set data style lines')

# Make the plot items
plot1 = Gnuplot.PlotIte ms.Data(origina l, title="Original ")
plot2 = Gnuplot.PlotIte ms.Data(expecte d, title="Expected ")
plot3 = Gnuplot.PlotIte ms.Data(actual, title="Acutal")
gp.plot(plot1, plot2, plot3)
return gp
def show_plots(orig inal, expected, actual):
gp = combine.plot( original, expected, actual)
raw_input("firs t")
gp = combine.bestfit (expected)
raw_input("seco nd")
gp = combine.bestfit (actual)
raw_input("thir d")

# --- combine_main.py ---
import combine

combine.show_pl ots([(2,3), (4,8), (5,9), (6,2)], [(1,7), (3,3), (4,5),
(5,6)], [(1,3), (3,10), (4,8), (7,9) ] )

[arslanburney]

Umm.... Tried this out too.... Laiken heres the error that this
gives..

Traceback (most recent call last):
File "D:\Questions\G radient and C\Gnuplot\Combi ning Best fit and
Plotting\combas d.py", line 3, in <module>
combine.show_pl ots([(2,3), (4,8), (5,9), (6,2)], [(1,7), (3,3),
(4,5), (5,6)], [(1,3), (3,10), (4,8), (7,9) ] )
File "D:\Questions\G radient and C\Gnuplot\Combi ning Best fit and
Plotting\combin e.py", line 54, in show_plots
gp = combine.plot( original, expected, actual)
NameError: global name 'combine' is not defined

Still confused though i get the instance part ur trying to tell me.

[Peter Otten]

ar**********@gm ail.com wrote:

Umm.... Tried this out too.... Laiken heres the error that this
gives..

Traceback (most recent call last):
File "D:\Questions\G radient and C\Gnuplot\Combi ning Best fit and
Plotting\combas d.py", line 3, in <module>
combine.show_pl ots([(2,3), (4,8), (5,9), (6,2)], [(1,7), (3,3),
(4,5), (5,6)], [(1,3), (3,10), (4,8), (7,9) ] )
File "D:\Questions\G radient and C\Gnuplot\Combi ning Best fit and
Plotting\combin e.py", line 54, in show_plots
gp = combine.plot( original, expected, actual)
NameError: global name 'combine' is not defined

Still confused though i get the instance part ur trying to tell me.

Sorry, it should have been

def show_plots(orig inal, expected, actual):
gp = plot( original, expected, actual)
raw_input("firs t")
gp = bestfit(expecte d)
raw_input("seco nd")
gp = bestfit(actual)
raw_input("thir d")
Peter

[arslanburney]

On Jun 13, 12:13*pm, Peter Otten <__pete...@web. dewrote:

arslanbur...@gm ail.com wrote:

Umm.... Tried this out too.... Laiken heres the error that this
gives..

Traceback (most recent call last):
* File "D:\Questions\G radient and C\Gnuplot\Combi ning Best fit and
Plotting\combas d.py", line 3, in <module>
* * combine.show_pl ots([(2,3), (4,8), (5,9), (6,2)], [(1,7), (3,3),
(4,5), (5,6)], [(1,3), (3,10), (4,8), (7,9) ] )
* File "D:\Questions\G radient and C\Gnuplot\Combi ning Best fit and
Plotting\combin e.py", line 54, in show_plots
* * gp = combine.plot( original, expected, actual)
NameError: global name 'combine' is not defined

Still confused though i get the instance part ur trying to tell me.

Sorry, it should have been

def show_plots(orig inal, expected, actual):
* * gp = plot( original, expected, actual)
* * raw_input("firs t")
* * gp = bestfit(expecte d)
* * raw_input("seco nd")
* * gp = bestfit(actual)
* * raw_input("thir d")

Peter

Tried that out too. No error however, best fit lines still not being
made on the graph. Only the 3 plot lines show up.

[Peter Otten]

ar**********@gm ail.com wrote:

Tried that out too. No error however, best fit lines still not being
made on the graph. Only the 3 plot lines show up.

Sorry, I don't know gnuplot, so I can't help you with any but the obvious
(read: Python) errors.

Peter

[Peter Otten]

ar**********@gm ail.com wrote:

Still confused though i get the instance part ur trying to tell me.

Tried that out too. No error however, best fit lines still not being
made on the graph. Only the 3 plot lines show up.

Gave it another shot. You might want something like

from __future__ import division
import Gnuplot

def bestfit(uinput, **kw):
sigmax = sigmay = sigmaxy = sigmaxsq = 0

for x, y in uinput:
sigmax += x
sigmay += y
sigmaxy += x * y
sigmaxsq += x * x

n = len(uinput)
sigmaxwhl = sigmax * sigmax
sigmaxsigmay = sigmax * sigmay
num = sigmaxsigmay - n * sigmaxy
den = sigmaxwhl - n * sigmaxsq
num2 = sigmax * sigmaxy - sigmay * sigmaxsq
gradient = num / den
intercept = num2 / den

return Gnuplot.Func('% f * x+%f' % (gradient, intercept), **kw)

def plot(original, expected, actual):
gp = Gnuplot.Gnuplot ()
gp('set data style lines')

# Make the plot items
plot1 = Gnuplot.PlotIte ms.Data(origina l, title="Original ")
plot2 = Gnuplot.PlotIte ms.Data(expecte d, title="Expected ")
plot3 = Gnuplot.PlotIte ms.Data(actual, title="Actual")
bf2 = bestfit(expecte d, title="Best fit expected")
bf3 = bestfit(actual, title="Best fit actual")

gp.plot(plot1, plot2, plot3, bf2, bf3)
return gp
if __name__ == "__main__":
gp = plot( [(2,3), (4,8), (5,9), (6,2)], [(1,7), (3,3), (4,5), (5,6)],
[(1,3), (3,10), (4,8), (7,9) ] )
raw_input()

It's all in one file for simplicity. Note that I did not check the best fit
algorithm, just tried to simplify what you already had. Use at your own
risk.

Peter

[arslanburney]

Got the problem solved finally. Missed out theses two lines:

plot1 = Gnuplot.PlotIte ms.Data(origina l, title="Original ")
plot2 = Gnuplot.PlotIte ms.Data(expecte d, title="Expected ")
plot3 = Gnuplot.PlotIte ms.Data(actual, title="Acutal")
plot4 = Gnuplot.PlotIte ms.Func('%f * x+%f'%(bf1[0],bf1[1]), title
= "Expected Best Fit")
plot5 = Gnuplot.PlotIte ms.Func('%f * x+%f'%(bf2[0],bf2[1]), title
= "Actual Best Fit")

The last 2 ones.... thnx nyways