Items tagged with curve

Hi 

friend i want fit a curve regarding some data and fnction and how we can find the values of a,b,c and d for the following 

f=1-(8*a*b+6*c*d/(b*k*x))/(2*a*b+c*b*(1/(b*k*x)))

X := Vector([200, 210, 220, 230, 240, 250, 260, 270, 280, 290])

Y := Vector([.4172, .3030, .4668, .3317, .1276, .1303, .1733, .1451, .3466, .4125])

     Parallel curves on surfaces. The distance between the points of the curves is measured along the curves of intersection of the surface and perpendicular planes.
     (According to tradition, it also does not make sense.)

equidistant_curve_surface_MP.mw

 









 

 

Dear Community,

I've made a nonlinear curve fit with the Minimize routine (see attachment). What would be an easy and elegant way to rerun the model (Model) with the fitted values of a, b, c and plot the result together with the measured points in the same chart? I'm stuck here.

Tx in advance,

best regards

Andras

BroSzem_Data.xlsx

Nonlin_Curve_Fit.mw

 

from mathematica,

 

n = 5;
CalabiYau[z_, k1_, k2_] := Module[{z1 = Exp[2Pi I k1/n]Cosh[z]^(2/n), z2 = Exp[2Pi I k2/n]Sinh[z]^(2/n)}, {Re[z1], Re[z2], Cos[alpha]Im[z1] + Sin[alpha]Im[z2]}];
Do[alpha = (0.25 + t)Pi; Show[Graphics3D[Table[ParametricPlot3D[CalabiYau[x + I y, k1, k2], {x, -1, 1}, {y, 0, Pi/2}, DisplayFunction -> Identity, Compiled ->False][[1]], {k1, 0, n - 1}, {k2, 0, n - 1}], PlotRange -> 1.5{{-1, 1}, {-1, 1}, {-1, 1}}, ViewPoint -> {1, 1, 0}]], {t, 0, 1, 0.1}];

 

n := 5;

z1 := exp(2*3.14*I*k1/n)*cosh(z)^(2/n);
z2 := exp(2*3.14*I*k2/n)*sinh(z)^(2/n);

alpha = (0.25 + t)Pi;

xx := Re(z1);
yy := Re(z2);
uu := cos(alpha)*Im(z1) + sin(alpha)*Im(z2);

 

where k1, k2, alpha are variables

print([xx,yy,uu]);

i find algcurve has implicitize

how to use this implicitize to find 3d surface?

is there any other method to find?

 

i searched groebner basis can do this, but in mathematica is different from maple example

Hi,

 

I am having trouble in plotting the following surface (it is a quite complicated expression, but should be fine).

OwnSurface := [-Re(arctan(exp(I*Pi*(1/4))*(u^2+v^2)^(1/2)))-(1/2)*ln((1+(u^2+v^2)^2)^(1/2)), -arctan(1/((2*(u^2+v^2))^(1/2)-1))+7*Pi*(1/4), (1/8)*ln(u^2+v^2-(2*(u^2+v^2))^(1/2)+1)-(1/8)*ln(u^2+v^2+(2*(u^2+v^2))^(1/2)+1)-(1/4)*arctan(1/((2*(u^2+v^2))^(1/2)+1))+(1/4)*arctan(1/((2*(u^2+v^2))^(1/2)-1))];

plot3d(OwnSurface, u = -.4 .. .4, v = -.4 .. .4, labels = [x1, x2, x3]);

The only thing maple does is plotting a box with a diagonal line. How can I fix this?

 

I want to plot a curve of the form |z*e^(1-z)| = 1 (the Szego curve). I am not sure how to call complexplot() to make this happen. Just calling complexplot(abs(z*exp(1-z)) = 1) does not work, and I don't know what else to specify. Any help?

Spiral (equidistant) around the curve.  In this case, a spiral around the spiral.
So without any sense. 
spiral_around_curve.mw 
 
If we re-save the animation with the program Easy GIF Animator, its size is reduced by about 10 times, and sometimes much more.


Hello I have this assignment. I will translate it (because it is not english)

This is the assignment: [IMG]http://i68.tinypic.com/2cgoby9.jpg[/IMG]

(if u cant click on the above link, then u can see it here http://tinypic.com/view.php?pic=2cgoby9&s=9)

 

So it says:

-------

In an examination of young pigs' birth weight 853 newborn pigs were weighted. The weighting is shown in the table down below. 

 

[0,5-0,7] [0,7-0,9] [0,9-1,1] [1,1-1,3] [1,3-1,5] [1,5-1,7] [1,7-1,9] [1,9-2,1] [2,1-2,3] -> WEIGHT in kg

[26]            [43]       [102]       [145]        [171]      [196]     [119]       [42]          [9]      --> number of pigs

 

Draw a cumulative frequency curve of the weighting and determine the kvartils.

 

SO I usually do this in Maple, but this time I did a matrix but nothing happened.. I dont know how I should draw this curve? Help please. 

 

 

[IMG]http://i68.tinypic.com/2cgoby9.jpg[/IMG]

Hello,

I try to use a Catmull-Rom spline which has to match on several points.

I use a code extracted from the book "Geometry and curves with maple".

Here you can find an extract which is visible from google book :

I have slightly modified the initial procedure crom_2d. I didn't find the error in my procedure. May you help me to find the blocking point of my procedure ?

Here I attached my code:

CalculSplineMatmull-Rom.mw

Thank you for your help.

Suppose that we have the following curve on a unit sphere

r^2+z^2=1

phi=pi/3

-1<=z<=1

which is the implicit equation of a circle in "cylindrical coorinates" (r,phi,z) on the sphere.

How can I plot this curve without solving the implicit equation for r or z ?

Also, I don't want to make any parameterization.

Suppose I have the parametric equations of a circle

x=cost

y=sint

where t runs from 0 to 2*pi. How can I show the orientation of this parametric curve on a plot?

Hello,

I'm a very new beginner, and I have a question about getting the data of a curve from a JPG, without using manual measures an too getting more accurate datas.

I wish to fit the curve with a model. The JPG joined, from EU 2015, is about human thermoregulation. I still try to found a model with Mathematica but am uncertain seeing the result as illogic.

Did anyone write something to read curves from a JPG and get coordinates from these curves ? In the JPG, the curve is above, as an 'U'.

Thanks for your advice,

Milos.

How I can highlight p(1,1) and Q(2,4) on the curve f(x)=x^2?

Vahid Borji

I have the following code of a plot:

plot(
[
add(BS(bb[4], t, i, 3)*bb[1](i+1), i = 0..n),
add(BS(bb[4], t, i, 3)*bb[2](i+1), i = 0..n),
t = 0..1
],
color=red, axes=normal, scaling=constrained, numpoints=100, thickness=2
):

and I get the following error:

Error, (in BS) cannot determine if this expression is true or false: 0 <= t and t < .54901960784313725490196078431373

The problem is that, in the definition of BS, there are some conditions that depend on the variable t. It seems that Maple does not use a specific value of t when executing BS. My solution is to plot specific points, i.e., 

plot(
[
seq([add(BS(bb[4], h/5000, i, 3)*bb[1](i+1), i = 0..n),
add(BS(bb[4], h/5000, i, 3)*bb[2](i+1), i = 0..n)], h=0..5000)
],
color=red, axes=normal, scaling=constrained, numpoints=100, thickness=2
):

Can this be done in a more elegant way?

 

 

1 2 3 4 Page 1 of 4