0
votes
2answers
62 views

How can I put the results of TrigFactor function into a more convenient form?

a1 D11 Cos[n x] + a0 a1 D11 Cos[n x] + 1/2 a1 a3 D11 Cos[n x] + 1/2 a2 a4 D11 Cos[n x] I have a large trigonometric expression. Can I factor out different ...
0
votes
0answers
40 views

How to add a positive definiteness of a unsymmetric matrix as a constraint to a Findminimum problem

The problem is I have a function which has 33 variables, and which to minimize it in a given set of contraints. I have also a matrix consisting of these 33 variables. The condition is that this matrix ...
0
votes
2answers
125 views

Projectile motion in Mathematica using Euler's method [duplicate]

I need to write the equations of a ball in projectile motion (ignoring air friction) with an initial velocity of 40 m/s at an angle of 40° with respect to the horizontal. Specifically, I need to ...
0
votes
1answer
79 views

How to plot and visualize a single linear vector in 3D? [closed]

I have a vector (in physic) designated as F1=250cos(60)i+250cos(60)j+250cos(45)k, and i would like to see it in a 3D graphic with the axis centered at the origin, after what i would include other ...
0
votes
2answers
146 views

How to construct a linear feedback shift register

Are there any posts regarding the construction of a LFSR (Linear Feedback Shift Register) in Mathematica? I can't seem to find any and I am not sure how I would construct one.
0
votes
0answers
66 views

Determination of Ricci tensor and Scalar curvature from veirbeins

Consider the following metric: $ds^2=h(r)\bigg(dr^2+r^2\big(d\theta^2+\sin^2\theta ~d\phi^2+(d\psi+\cos\theta ~d\phi)^2\big)\bigg)$ We can try to compute the Ricci scalar of this metric by using ...
0
votes
1answer
115 views

Non linear model fit

I need to fit this, but for some reason I cannot... data = {{0.617,0.8}, {0.605,0.6}, {0.5997,0.4}, {0.5972,0.2}, {0.5985,0.1}}; soln = NonlinearModelFit[data, {y - 2478.82*wlog[kc + 1]}, {y,w,k}, ...
0
votes
1answer
104 views

Estimating Parameters of a Custom Distribution

The problem is I can not get estimation of parameters of any custom probability distribution (distributions are not built in Mathematica), here is an example: First: I entered random numbers of ...
0
votes
0answers
155 views

Generate Matlab figure

I am currently working on a project. Because of lack of communication between my team mates and I, I did most of the work (and the graphical figures) in mathematica. Now, I have to pass all the ...
0
votes
1answer
68 views

Get all variables in an expression with Variables[]

"\[Phi]" <> "1"; Variables[%] Exp["\[Phi]" <> "1"]; Variables[%] Exp[Subscript[\[Phi], 1]]; Variables[%] Say I have lots of variables used for ...
0
votes
2answers
119 views

Suppressing reduction in fraction box size in multi-level fractions [duplicate]

Mathematica display complex fractions like this, the second x look smaller, I want it look like this, how can I get it in Mathematica?
0
votes
1answer
165 views

eigenvector bug also for matrix with numeric value [closed]

I just realize that probably there is a bug also in calculating the eigenvector of a matrix with numeric values (see here for bug in eigenvector calculation with symbolic value). In particular in my ...
0
votes
1answer
238 views

Show Progressbar after pressing a button

I've recently struggling with Buttons. So I understand Buttons have the form Button["text",action]. Now I want the action to be ...
0
votes
1answer
138 views

How to solve this nonlinear 2 by 2 equations?

I have a equation (x^2 + q1^2 - y^2)/2*(x + q1 - y) + (1 - 2*a)*q + 2*F = 2*(1 - a)*c[q] in q(variable) with parameters q1,a,F and function c(in variable q also, and I define it outside Solve so I can ...
0
votes
3answers
162 views

Why is 1. x (Times[1.`, x]) not simplified to x?

This is maybe a silly question, but I could not think of any logical reason why it is not simplified automatically. I was working with a big linear equation system with some constrained inequalities ...
0
votes
1answer
130 views

Defining new Cellular Automata rule [closed]

I want to define a new Cellular Automata rule as follows {{1, _, 1} -> 0, {1, _, 0} -> 1, {0, _, 1} -> 1, {0, _, 0} -> 0} where _ represents Blank ...
0
votes
1answer
285 views

How to use `FindRoot` to solve an equation containing a parameter?

I'm trying to derive some of the results of the following paper: Electrodynamics of semiconductor-coated noble metal nanoshells, JT Manassah - Physical Review A In the paper there is matrix $\mathbf ...
0
votes
1answer
87 views
0
votes
1answer
40 views

save all inputs as list [duplicate]

I received three results of calculations: {k->0.190729} {k->0.197575} {k->0.249319} Could you help me write the results in the following form: ...
0
votes
2answers
174 views

Fraction of fibers that have failed

I have the following to set into mathematica. Assume a stress(sigma) applied on a specimen which has a number of fibers within it. All fibers that have a strength less than the applied stress should ...
0
votes
1answer
75 views

nested series expansion

I have to invert the following matrix in which the functions U[t,x,y,r] and K[t,x,y,r] and all their derivatives are "small"; ...
0
votes
1answer
122 views

A problem with set values

The following code is just an example to clearly explain my problem. Assume that : ...
0
votes
2answers
147 views

How to do symbolic definite integral without copy and paste the intermediate results?

I am do a symbolic definite integral, I am doing it like this: Integrate[1/Sqrt[(ϵ + u)^2 + Δ^2], ϵ] // FullSimplify It gives an output: ...
0
votes
2answers
131 views

The precision of the number

I have problem in Mathematica with unnecessary rounding which is caused by high precision. For example I have value a = 2.052685846*10^-1865, when I make ...
0
votes
1answer
142 views

How can I obtain more significant digits? [duplicate]

I type f1[x_] := 12 x^5 - 975 x^4 + 28000 x^3 - 345000 x^2 + 1800000 x N[f1[15.5], 15] and obtain 3.74112*10^6 BUT It´s not true!!! the result is larger than ...
0
votes
1answer
1k views

How can I draw this particular phase diagram in Mathematica? [duplicate]

Sketch the phase diagram for systems with the following velocity functions where a and b are constants with ...
0
votes
1answer
264 views

Using an image as a moving object in an animation

I have following animation: ...
0
votes
1answer
63 views

Mapping a function of two arguments where the 2nd arg has a fixed value

I create three random images: i1 = Image[RandomReal[1, {8, 12, 3}]]; i2 = Image[RandomReal[1, {8, 12, 3}]]; i3 = Image[RandomReal[1, {8, 12, 3}]]; I can scale a ...
0
votes
1answer
134 views

Explicit, closed formula for recursive integral as a function of the recursive parameter

This is a follow-up of this question/answer. I'm working on a recursive integral more complicated than the one on the linked question, but this one can be used as an example. I would like to obtain ...
0
votes
1answer
211 views

Passing lists to functions in a manner that works like pass-by-reference in other languages?

Is it possible to use a list as a variable, i.e., to pass it by reference to a function? In particular, I have a two-dimensional array and a function to get one element specified by its position: ...
0
votes
3answers
156 views

Speed up manipulate by exporting each step as an image

Consider a manipulate function such as: ...
0
votes
2answers
99 views

Gaps in plots of equation solution from parameter

I'm trying to plot solution of system of equations as a function of parameter ...
0
votes
1answer
175 views

How do I include both text and variables in Input[ ]?

I want to prompt a user to input an answer to a question. I want the question that pops up to have both text and numbers or strings. For example, if I ask the user to give a name to something in the ...
0
votes
1answer
114 views

Can I force a function to quit and return some value after a certain amount of time has passed during its evaluation?

Imagine I provide some random input to function like FindInstance[], and I observe that, despite the existence of good solutions, the function will, with some ...
0
votes
1answer
1k views

integration on real domain only!

i am trying to integrate a real valued function. For some reason, Mathematica gives an answer in the complex domain. I'd be grateful for your answers. Here is the integral: ...
0
votes
1answer
859 views

How to show legend in a combined plot of many lists,

I am having trouble with adding a legend to a plot. The example I discuss here is simpler than my real problem, but describes it well. I have a vector, called X with dimensions (100 x 6). I use the ...
0
votes
2answers
618 views

Integral with the derivative of Dirac delta does not evaluate correctly?

Integrate[DiracDelta'[y - z] DiracDelta[x - z], {z, -Infinity, Infinity}, Assumptions -> x \[Element] Reals && x \[Element] Reals]
0
votes
0answers
115 views

Good Introduction / Tutorial to Mathematica **Books** [duplicate]

Possible Duplicate: Where can I find examples of good Mathematica programming practice? I'm a high school senior and am using Mathematica for a research project. However, I find it a bit ...
0
votes
1answer
960 views

How to get data from For loops to plot it?

How can I get data from For loops to use in ListStreamDensityPlot? I tried AppendTo, but it ...
0
votes
1answer
661 views

Plot 3D vector that is a function of one variable

I have a function, r[t], which is a piecewise function that generates a 3D vector. It looks like this: ...
-1
votes
1answer
104 views

Implementing the Golden Section Rule

I am attempting to write a code which brackets the minimum of a unimodal function, using the Golden Section Method Below. I am have serious issues debugging my program though, any help will be ...
-1
votes
1answer
85 views

Reduced interpolation order [closed]

I have a problem with Interpolation - the order is reduced to 1 no matter what, but I need a quadratic interpolation order. The ...
-1
votes
2answers
548 views

How to simplify expressions containing derivatives

Is there a way to reverse the application of derivative rules in order to simplify expressions including derivatives? e.g. in Mathematica code: Want to go from ...
-2
votes
1answer
57 views

Solve For X inside arc-cos function (with division) [closed]

Very basic but I've been stuck for more than 12 hours trying to solver this equation 20=360/(arccos(X/3200)*2) Can anyone solve X? and explain what exactly you ...
-2
votes
1answer
97 views

How to integrate a table? [closed]

I have the following Table (dy/dx)={24,24.5,25,25.4} How do I proceed to interpolate the table and compute Integrate[Sqrt[1+(dy/dx)^2],{x,65,68}] ?
-2
votes
2answers
121 views

plot data with small differences

I want to plot data with very small differences. I can't see the differences in my plot:
-2
votes
1answer
191 views

How to pass arguments between functions

I have two Functions, f[] and g[]. f is passed some values ,say ...
-3
votes
0answers
28 views

Recursion with an exception [duplicate]

I need to print the first 7 members of the sequence a[n] with its reccurence formula a[n+1]=7*a[n]+n, where a[1]=1 and the digit 7 dosnt occur.
-3
votes
1answer
114 views

Integration with mathematica? [closed]

I am very new to Mathematica. I am trying to evaluate ∫ (1+lnx)Sqrt(1+(xlnx)^2) using Mathematica. I know a substitution must be done so I have set ...
-3
votes
1answer
397 views

import Excel sheets by name

I'm importing data from Excel. It appears that the sheet number needed in the Import statement is taken from the order that the sheets appear in the open Excel file. I need to import 2 of the sheets ...

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