Hello,

I have a problem. I want to make plot 3d for pressure drop in diffuser by posuille formula,

but with increasing of "l"(length of channel) graph shows wrong pressure drop. Normally with i increasing of "L" we should have...

> restart; R := 8.314;print(??); # input placeholder> G1[1] := piecewise(`and`(T > 298, T < 700), -7976.15+137.093038*T-24.3671976*T*log(T)-0.1884662e-2*T^2-0.877664e-6*T^3+74092/T, `and`(T >= 700, T < 933), -11276.24+223.048446*T-38.5844296*T*log(T)+0.18531982e-1*T^2-0.5764227e-5*T^3+74092/T, `and`(T >= 933, T < 2900), -11278.361+188.684136*T-31.748192*T*log(T)-0.1230622e29/T^9, 0);print(??); # input placeholder

> G1[2] := piecewise(`and`(T > 298, T < 700...

The system consists of 3 equationsHow can you single out one of the solutions in obtaining module and plot for it?
a := 1; m := 1/64 
l1 := 2*(diff(ur(e, t), t))+(1+tanh((1/20)*e))*(diff(ui(e, t), `$`(e, 2)))+2*a*(ui(e, t)*ur(e, t)*ur(e, t)+(ui(e, t)*ui(e, t))*ui(e, t))+m*ui(e, t)*(diff(ur(e, t)^2, e))+m*ui(e, t)*(diff(ui(e, t)*ui(e, t), e)) = 0 
l2 := -2*(diff(ui(e, t), t))+(1+tanh((1/20)*e))*(diff(ur(e, t), `$`(e, 2)))+2*a*(ur(e, t...

Let say that you have two datasets:

restart:
with(MyFinance):
z1 := GetCSV("http://www.quandl.com/api/v1/datasets/USER_18Q/18R.csv?&auth_token=BXckVSG3twWkV272c9Q4&trim_start=1968-04-01&trim_end=2013-04-12&collapse=daily&transformation=rdiff&sort_order=desc");
z2 := GetCSV("http://www.quandl.com/api/v1/datasets/USER_18Q/1EV.csv?&auth_token=BXckVSG3twWkV272c9Q4&trim_start=1994-01-03&trim_end=2013-04-12&collapse=daily&...

When I solve a systems of equations, fsolve gives the solution

.

I now want want to define the variables x, y and z as respectively 5, 6 and 1 - but without copying the solution. Because this is a solution that I get in a loop, so it changes in every step. Maybe there is a easy way to put it in a vector?

I often have large matrices and have to grab only every nth column or row (for plotting

for example). So far I've been doing it this way:

nthColumns:=proc(v_m, v_n)  

v_m[..,[seq(i, i=1..rtable_size(v_m)[2], v_n)]]

end;

nthRows:=proc(v_m, v_n) 

 v_m[[seq(i, i=1..rtable_size(v_m)[1], v_n)],..]

end;

A := LinearAlgebra:-RandomMatrix(20, 20, outputoptions = [datatype = float[8]]);

I only want to display 'position' in animation while tend <= 12:
This is the trial:

restart:with(plots):
for tend from 0 to 50
while (tend <= 12) do
pos:=animate(textplot3d,[[-1.8,0,alpha*tend, 'position']], tend=0..50,frames=150);
od;
display(pos);

I receive error messages:
error, (in plots/animate) 0=0..50 is an invalid animation range

Then I try:

restart:with(plots):
while (tend <= 12) do

Helo every one,

I'm trying to find the positive real root from:

and substitute it in:

my prog is:

eq5:=u->-3*b*k*u^2-3*b*k^2*u^4-k^3*u^6*b+k*u+5*k^2*u^3-b:  

                   (solve(eq5(u),u)): S:=array([...

I am using Maple 15 and every time I try to plot this equation it doesnt seem to want to plot. This is the code I keep trying to input:

plot(3*e^(-x)*x-e^(-x)-1.5*e^(-x)*(x^2)+e^(-x)*(x^2)*log(x),x=0..9,y=-1..0.6);

Every time I get "Plotting Error, empty plot"

The equation came from the original differential equation .5(d^2y/dx^2)+(dy/dx)+.5y(x)=ln(x)e^(-x)

 Also When i try to plot this equation:

-.5*e^(-10*x)*sin(10*x)-.5*e^(-10*x)*cos(10*x)+(3/2)=300

Solve for x in the following expression.

log x=-4

I use the following commands to export a graph to a file:

plotsetup(gif, plotoutput=cat(filefolder,examplenr,".gif")):
print(display([pol],color=grey,scaling=constrained,axes=none,view=[0..100,0..100])):

filefolder is defined as a complete path: filefolder:="D:/TopUp/models/vergelijking/":
And pol is a pol:=plottools[polygon](polygonlist,color=grey): 

This works fine when I use it directly in a Maple worksheet.

However, if I save...

We want to fit

f(x) = a_0 + a_1 *x + a_2 * x^2 + ... + a_n * x^n

to the data (x_i,f(x_i)) for i = 0 ... n.

It will give rise to the following system

[ a_i ] = [A]^{-1} * [ f(x_i)].

Here [a_i] = [ a_1 a_2 a_3 ... a_n], 

[A] = [ 1 x_0 x_0^2 ... x_0^n ; 1 x_1 x_1^2 ... x_1^n ; 1 x_2 x_2^2 ... x_2^n ; ... ; 1 x_n x_n^2 ... x_n^n]

and 

[f(x_i)] = [f(x_0) f(x_1) f(x_2) ... f(x_n)].

I want to know how to take the fourier transform of a solution to an IVP obtained using dsolve/numeric and consequently plot the transform. any ideas?

I have an animated spacecurve with arrow:

restart:with(plots):

p4:=animate(arrow,[<cos(tend),sin(tend),0.9 tend>,<-cos(tend),-sin(tend),0>,color=red],tend=0..50,axes=boxed,frames=150);

I succeed in putting text at basis of arrow:

l3:=animate(textplot3d,[[cos(tend),sin(tend), 0.9 tend, 'basis'],color=black,align={BELOW},font=[TIMES,ROMAN,14]],tend=0..50,frames=150);

I like tot put text at the end of the arrow. This is my 'progress':

Hello evrybody,

my first question here.

i'm a engineer studend in electronic and i'm working on the inverted pendulum problem at my university.

so i need to use the lagrange way to get my equations in the good form.

i have this equations :