MaplePrimes - Maple 10 Posts and Questions

Warning, solution may have been lost

wangxj — Sat, 24 Jan 2015 12:14:02 Z

Hi! when i'm trying to solve, i get the following warning: Warning, solutions may have been lost.

The equations i'm trying to solve are as the following:

>A=0.1;

> D=0.19;

> eqns:={y^1.5-9/8*B^0.5*y+3/4*x*y^0.5-3/4*(Pi/3)^0.5*[1+(1+3/4*(Pi/3)*(B*(1+x^2))^0.5)*x^2]/(1+x^2)^0.5=0, Pi/2-3*D=8/3*y^3+x*y^2+4*B^0.5*[1/3*B*y^1.5-2/45*B^2.5-3/2*y^2.5]-9/2*B*(1/3*B*y-3/40*B^2-3/4*y^2)-3*x*B^0.5*[1/3*B*y^0.5-1/7*B^1.5-1/2*y^1.5],B=A/(1+x^2)};

> vars:={x,y,B};

> solve(eqns,vars);

Warning, solutions may have been lost

What am i doing wrong?

Many thanks!

Calling Part of Piecewise Function

fatihuludag — Mon, 05 May 2014 22:45:20 Z

f:=piecewise(x>0,1+x,x=0,2,x<0,1+x^2)

in my work i must use some parts of this piecewise function.

But i don't know how can i call the part that i will use.

How can i do that ?

Thanks for help

How do I solve this integration in Maple?

dolby87 — Mon, 28 Apr 2014 01:15:48 Z

Hai everyone.

I try to double integrate this generalized extreme distribution.

q[p] := 6.256: h := .8; t[c] := .45: S[di] := 0: k[v] := .32639: mu[v] := -0.1786e-1: sigma[v] := 2.1694: k[t] := .36132: mu[t] := .63543: sigma[t] := 3.1183:

int(exp(-(1+k[v]*(v-mu[v])/sigma[v])^(-1/k[v]))*(1+k[v]*(v-mu[v])/sigma[v])^(-1-1/k[v])*exp(-(1+k[t]*(t-mu[t])/sigma[t])^(-1/k[t]))*(1+k[t]*(t-mu[t])/sigma[t])^(-1-1/k[t])/(sigma[v]*sigma[t]), [v = q[p]/(2*h*t)+q[p]*t[c]/(2*h)+S[di] .. infinity, t = 0 .. infinity]);

however, I got an error, as follow:

Error, (in assuming) when calling '`root/fraction`'. Received: 'numeric exception: overflow'

Any recomendations and tips to solve this integration? or this integration may cannot solve?

Thank you.

Pointplot with different colors

smith_alpha — Thu, 20 Feb 2014 05:29:56 Z

I have 20 datapoints in two groups. I may name them as f[1],...,f[10];g[1],...,g[10]. f[1]:=[1.2,3.5] etc

I would like to plot these 20 points

(1) in one plot

(2) f[1]~f[10] in one color; g[1]~g[10] in another color.

I checked http://www.maplesoft.com/support/help/Maple/view.aspx?path=plots%2fpointplot

and did not get the point :(

Do you any suggestion what can I do to realize the aims (1) and (2)?

Thank you very much in advance!

Loading random number

smith_alpha — Wed, 19 Feb 2014 19:52:39 Z

Hi,

I tried to use generated random as following

***

for j from 1 to 5 do
    c:=rand(0..1):
    d:=c();
    print(`random number`,c(),d);

    if c()=1 then

       print(`Y`)
    else
     print(`N`);
    end if;
end do:

***

The output is

****

                      random number, 1, 0

                               Y

                      random number, 1, 1

                               Y

                      random number, 1, 1

                               N

                      random number, 1, 1

                               N

                      random number, 0, 0

                               N

****

Why the output numbers in one line are different? And Using "if" sentence seems do not correspond to the printed "c()" value..

Thank you very much in advance!

unable to execute add

felixiao — Fri, 29 Mar 2013 15:46:45 Z

Dear Sir, I want to know why the procedure appear the error : (in U1) unable to execute add.

My procedure:

restart:
>
> h0:=0.156;
> d:=0.32*h0;
> l:=1;
> h1:=h0-d;
> h2:=h0+d;
> h5:=evalf(2/3*h0);
> h7:=h0;
> s1:=evalf(2/3);
> s2:=evalf(2/3);
> g:=9.8;
> d1:=1;
> Term:=10;
> Num:=5:
> n:=1:
>
>
> for N from 1 to Num do
> k0:=evalf(0.5*Pi+2*(N-1)*Pi/(Num-1)):
> tau0:=evalf(k0*h0):
> omega:=evalf((g*k0*tanh(k0*h0))^(1/2)):
> E:=g/(omega)^2:
> k1:=abs(fsolve(omega^2=g*k*tanh(k*h1),k)):
> tau1:=evalf(k1*h1):
> k2:=abs(fsolve(omega^2=g*k*tanh(k*h2),k)):
> tau2:=evalf(k2*h2):
> k5:=abs(fsolve(omega^2=g*k*tanh(k*h5),k)):
> tau5:=evalf(k5*h5):
>
> zeta1:=evalf((tau0+tau5)/2):
>
> Q:=tau->(16*tau^4+32*tau^3*sinh(2*tau)-9*sinh(2*tau)*sinh(4*tau)+12*tau*(tau+sinh(2*tau))*((cosh(2*tau))^2-2*cosh(2*tau)+3))/3/(2*tau+sinh(2*tau))^4; # ding yi han shu
>
> CCC:=unapply(taylor(2/sinh(2*tau),tau=zeta1,Term+1),tau):
> DDD:=unapply(taylor((1+2*tau/sinh(2*tau))^2*(1/s1^2+Q(tau)),tau=zeta1,Term+1),tau):
>
> for i from 0 to Term do
> u[i]:=coeff(CCC(tau),tau-zeta1,i);
> v[i]:=coeff(DDD(tau),tau-zeta1,i);
> end do;
>
> i:='i':
>
> c[0]:=1:
> c[1]:=0:
> d[0]:=0:
> d[1]:=1:
>
> for p from 2 to Term do
> c[p]:=-1/p/(p-1)*add((p-i-1)*u[i]*c[p-i-1]+v[i]*c[p-i-2],i=0..p-2);
> d[p]:=-1/p/(p-1)*add((p-i-1)*u[i]*d[p-i-1]+v[i]*d[p-i-2],i=0..p-2);
> end do:
>
> Term1:=i-1;
> f:=()->zeta1;
> U1:=tau->add(c[p]*(tau-f())^(p),p=0..Term1-1);
> U1(tau0);
> end do;