Plotting graph on pys60

korakot (Korakot Chaovavanich) — Sun, 19 Feb 2006 05:56:51 GMT

Here's the first step towards porting matplotlib to pys60.
I try to replicate some easy examples in
matplotlib tutorial.

First, we need a float range function.



from __future__ import generators



def arange(start, stop=None, step=None):

    if stop is None:

        stop = float(start)

        start = 0.0

    if step is None:

        step = 1.0

    cur = float(start)

    while cur < stop:

        yield cur

        cur += step

Then, a function to draw the axes and ticks.
In the future, this should be called automatically from plot().



from appuifw import *

app.body = canvas = Canvas()

width, height = canvas.size



def axes(xyrange, position=[18, height-11, width-10, 10], formatter=lambda x:x):

    global left, bottom, right, top, min_x, min_y, scale_x, scale_y

    left, bottom, right, top = position

    min_x, max_x, step_x, min_y, max_y, step_y = xyrange

    scale_x = float(right-left)/(max_x-min_x)

    scale_y = float(bottom-top)/(max_y-min_y)

    canvas.clear()

    canvas.rectangle([(left,top), (right+1, bottom+1)], 0)

    for x in arange(min_x, max_x, step_x):

        canvas.text((14+scale_x*(x-min_x), height-1), unicode(formatter(x)))

        canvas.point((left+scale_x*(x-min_x), bottom-1), 0)

        canvas.point((left+scale_x*(x-min_x), top+1), 0)

    for y in arange(min_y, max_y, step_y):

        canvas.text((2, bottom+2-scale_y*(y-min_y)), unicode(formatter(y)))

        canvas.point((left+1, bottom-scale_y*(y-min_y)), 0)

        canvas.point((right-1, bottom-scale_y*(y-min_y)), 0)

And lastly, the plot function. Now it has only a few features.
More will be added depending on what is needed.



def plot(xs, ys=None):

    if ys==None:

        ys = xs

        xs = range(len(ys))

    last = left+(xs[0]-min_x)*scale_x, bottom-(ys[0]-min_y)*scale_y

    for i in range(1, len(ys)):

        p = left+(xs[i]-min_x)*scale_x, bottom-(ys[i]-min_y)*scale_y

        canvas.line([last, p], 0x00000ff)

        last = p

    canvas.point(last, 0x0000ff)

When we want to plot a graph, we called both axes() and plot()



# a straight line

>>> axes([0,3.1,.5, 1,4.1,.5])

>>> plot([1,2,3,4])



# a parabola y = x^2

>>> axes([1,4.1,1, 0,16.1,2], formatter=int)

>>> plot([1,2,3,4], [1,4,9,16])

See the sreenshot of the first.

Read CSV and plot

dandye (Dan Dye) — Tue, 04 Oct 2005 06:41:53 GMT



 oaks <- read.table("assign1/oaksdf.csv",sep=",")

 oakpts <- as.points(oaks[,1],oaks[,2])

 plot(oakpts)

DZone Snippets: plot code

Plotting graph on pys60

Read CSV and plot