## 135 Reputation

13 years, 259 days

## artificial ECG signal...

Maple

j:=500:tp:=0.07*j:Ap:=0.25:Aq:=0.3:tq:=0.03*j:tr1:=0.05*j:Ar:=2:As:=0.4:tr2:=0.04*j:ts:=0.04*j:tt:=0.17*j:At:=0.4:
u1:=0:
u2:=(Ap/2)*(sin((2*Pi*t/tp)+(3*Pi/2))+1);
u3:=0:
u4:=-(Aq/tq)*t:
u5:=(((Ar+ Aq)/tr1)*t)-Aq:
u6:=-(((Ar+ As)/tr2)*t)+Ar:
u7:=((As/ts)*t)- As:
u8:=0:
u9:=(At/2)*(sin((2*Pi*t/tt)+(3*Pi/2))+1):
u10:=0:
u2 := -0.1250000000 cos(0.1795195802 t) + 0.1250000000

r1:=plot([u1],t=1..0.1*j):
r2:=plot([u2],t=1..tp):
r3:=plot([u3],t=1..0.08*j):
r4:=plot([u4],t=1..tq):
r5:=plot([u5],t=1..tr1):
r6:=plot([u6],t=1..tr2):
r7:=plot([u7],t=1..ts):
r8:=plot([u8],t=1..0.1*j):
r9:=plot([u9],t=1..tt):
r10:=plot([u10],t=1..0.08*j):
with(plots):
display(r1,r2,r3,r4,r5,r6,r7,r8,r9,r10,view=[0..100,-1..3],axes=boxed);

the same above code works in matlab

in maple it isnot

## integration of exponential * sin(error)...

Maple

Hi

Is there a way to solve it numericall

evalf(int(exp((5+I*6)*x)*sin(1+erf(x)),x=-to..to));

evalf(int(exp((5+I*6)*x)*cos(1+erf(x)),x=-to..to));

## trigonometric of error functions...

Maple

Hi all

trying to find analytically sin(erf(t)) and cos(erf (t)) rather than numerically

## contour plot of implicit expression...

Maple

Hi,

the foolowing code is for contour plot at Delta =-12.71 but there is somthing coulnd understand not works

I dont know why this not work

restart:
with(plots):

Omega:=0:lambda:=1:
gamma1:=8*Pi:
gamma2:=0.002*Pi:
x1:=100*Pi:
omega2:=200*Pi:
gamma0:=0.2*Pi:
G:=20*Pi:

lambda1:=(1/(2*Pi))*(G*Omega*gamma0/(2*(0.25*gamma0^2+Delta^2))):
lambda2:=(1/(2*Pi))*(-G*Omega*Delta/((0.25*gamma0^2+Delta^2))):
lambda3:=(1/(2*Pi))*gamma1+lambda1:
lambda4:=(1/(2*Pi))*(lambda*Delta-G^2*Delta/(0.25*gamma0^2+Delta^2)):
lambda5:=(1/(2*Pi))*(2*x1^2*omega2/((omega2^2+gamma2^2))):
f:=epsilon=(lambda1+sqrt(-lambda2^2+Y^2*(lambda3^2+(lambda4-lambda5*Y^2)^2))):

implicitplot3d(f, epsilon=0..20,Y = 0 .. 1,Delta=-40*Pi..40*Pi, labels=[epsilon,X,Delta],tickmarks=[3,3,3],style=surface);

contourplot(solve(f,Delta),epsilon=-20..20,Y=0..1,contours=[-12.71],axes=boxed,thickness=2,color=black,font=[1,1,18],tickmarks=[2, 2],linestyle=1, numpoints=50000);

## solve the sys of ODE of diff(x(t),y(t),...

Maple

the following maple code is to solve the SYS of ODE x',y',z'

then plot z' agianst t

i got confused each plot give me zero

N:=1:M:=sqrt(N*(N+1)):N1:=1+N:w:=10:f:=1;
f := 1

ini1:= x(0)=0.5,y(0)=0.5,z(0)=0;
ini1 := x(0) = 0.5, y(0) = 0.5, z(0) = 0
var:={x(t),y(t),z(t)}:
dsys:={diff(z(t),t)=-(N1+M*cos(2*w*t))*z(t)-1+f*(x(t)+y(t)), diff(x(t),t)=-(N1-I*w-2*M*exp(-2*I*w*t))*x(t)-f*(N1+(z(t)))-2*f*M*exp(2*I*w*t),diff(y(t),t)=-(N1+I*w-2*M*exp(2*I*w*t))*y(t)-f*(N1+(z(t)))-2*f*M*exp(-2*I*w*t)}:
zd:=diff(z(t),t);
d
zd := --- z(t)
dt
res:=dsolve(dsys union {x(0)=0.5,y(0)=0.5,z(0)=0},numeric,output=listprocedure):
tit:=sprintf("F=%g,N=%g",f,N):

P1:=plots[odeplot](res,[[t,(zd)]],0..6,axes=boxed,titlefont=[SYMBOL,14],font=[1,1,18],color=blue,linestyle=1,tickmarks=[3, 4],font=[1,1,14],thickness=2,titlefont=[SYMBOL,12]);

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