Ok, thanks. This seems works well.
The only thing which had to be change is to replace "**" (power)
with the usual "^"
The code below works well in jhepwork
(shows the function and its differential on the same plot)
*************************************************************
from java.awt import Color
from jhplot import *
c1 = HPlot("Canvas")
c1.setAutoRange()
c1.setGTitle("Example", Color.red)
c1.setNameX("Xaxis")
c1.setNameY("Yaxis")
c1.setName("Canvas title")
c1.visible()
c1.setAutoRange()
func="2*exp(-x*x/50)+sin(pi*x)/x"
f1 = F1D(func, 1.0, 10.0)
c1.draw(f1)
# use sympy
from sympy import *
x = Symbol('x')
a=diff(S(func), x)
ff=str(a).replace("**","^")
f2 = F1D(ff, 1.0, 10.0)
f2.setTitle("Differential")
f2.setColor(Color.green)
c1.draw(f2)
# export to some image (png,eps,pdf,jpeg...)
# c1.export(Editor.DocMasterName()+".png")
*********************************************************
On Sun, Jul 5, 2009 at 5:32 PM, Aaron S. Meurer <asmeu...@gmail.com> wrote:
>
> Hi, I'm not completely clear on what you are doing, as I don't use
> jython, but couldn't you just use str(), as in
>
> >>> a = str(diff(2*exp(-x*x/50)+sin(pi*x)/x, x))
> >>> type(a)
> <type 'str'>
> >>> F1D(a) # probably works now
>
> Also, you can use sympify() or just S() to convert from a string to a
> SymPy expression:
>
> >>> func = func="2*exp(-x*x/50)+sin(pi*x)/x"
> >>> print S(diff(func,x))
> -sin(pi*x)/x**2 + pi*cos(pi*x)/x - 2*x*exp(-x**2/50)/25
>
>
> On Jul 5, 2009, at 7:35 AM, sergei175 wrote:
>
> >
> >
> > Hi,
> >
> > Sympy seems is rather advanced and useful project.
> >
> > I've tried to test it using jhepwork, and even included it into
> > http://jwork.org/jhepwork/download/
> > (version 2.0) for test purpose (directory python/packages)
> >
> > Apparently, one can run sympy using Jython (v2.5) and Java !
> > A code snipped is below. Load it into the jHepWork IDE
> > editor and press the button [run].
> >
> > However, there is on feature I want to understand. To plot a function
> > as in the example below using F1D class, I need to pass a string
> > representing this function. However, simpy cannot accept strings for
> > the
> > statements such as diff() or integral(). In the below example, what I
> > want
> > to do is to type "diff(func,x)".
> >
> > Further, if I want to plot the result of "diff" or integration, I
> > need again a string
> > representing the output function and pass it to the F1D class as in
> > the example.
> > How can I do this?
> >
> > thanks, Sergei
> >
> > ********************************************************
> > # jHepWork Jython example
> >
> > from java.awt import Font,Color
> > from jhplot import *
> >
> > c1 = HPlot("Canvas")
> > c1.setAutoRange()
> >
> > c1.setGTitle("Example", Color.red)
> > c1.setNameX("X")
> > c1.setNameY("Y")
> > c1.setName("Simpy example")
> > c1.visible()
> > c1.setAutoRange()
> >
> > # draw function
> > func="2*exp(-x*x/50)+sin(pi*x)/x"
> > f1 = F1D(func, -2.0, 5.0)
> > c1.draw(f1)
> >
> > # use sympy
> > from sympy import *
> > x = Symbol('x')
> > print diff(2*exp(-x*x/50)+sin(pi*x)/x, x)
> >
> > # how to get string with the result
> > # to build F1D with results for drawing?
> >
> > # export to some image (png,eps,pdf,jpeg...)
> > # c1.export(Editor.DocMasterName()+".png")
> >
> > >
>
>
> >
>
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