Date: Sep 15, 2013 7:00 AM
Author: Bob Hanlon
Subject: Re: multiintegral and table

You cannot use _ (represents Blank[ ] ) in a variable or function name.

f1[x_, y_] = Integrate[2*y + x^2, {x, 0, 1}, {y, 0, x}]

7/12

f2[x_, y_, Q_] = Integrate[2*y + x^2*Q, {x, 0, 1}, {y, 0, x}]

1/3 + Q/4

ftotal[x_, y_, Q_] = f1[x, y] + f2[x, y, Q]

11/12 + Q/4

dataxx = Table[{Q, ftotal[x, y, Q]}, {Q, 0, 10, 1/400}];

ListPlot[dataxx]

Your function ftotal lends itself to using much sparser data sampling

dataxx2 = Table[{Q, ftotal[x, y, Q]}, {Q, 0, 10, 5}]

{{0, 11/12}, {5, 13/6}, {10, 41/12}}

ListPlot[dataxx2, Joined -> True, PlotStyle -> Thick]

ListLinePlot[dataxx2, PlotStyle -> Thick]

Bob Hanlon

On Sat, Sep 14, 2013 at 6:03 AM, Parada Hutauruk <phutauruk@gmail.com>wrote:

> Dear all,

>

> I have a function

>

> f_1 [x_,y_] = Integrate[2*y + x^2, {x,0,1},{y,0,x}]

>

> f_2 [x_,y_,Q_] = Integrate[2*y +x^2*Q, {x,0,1},{y,0,x}]

>

> f_total [x_,y_,Q_] = f_1[x,y] + f_2[x,y,Q]

>

> Then I want to plot the f total using table with Q start from 0 to 10 with

> increment 0.0025.

>

> I have defined by

>

> dataxx = Table[{Q,f_total[x,y,Q]}, {Q, 0,10, 0.0025}]

>

> And Plot the data on the table by

>

> ListPlot[dataxx]

>

> But when I evaluate the function, it took a long time and the plot is not

> yielded. Could anyone help me please to find the bug? I really appreciate

> for help.

>

> Thanks,

> PTPH

>

>