Questions tagged [piecewise]

Questions about the Piecewise function, which is represented by different expressions for different ranges of values of its independent variable.

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51 views

Error in drawing a Piecewise function!

I want to plot the piecewise function (FP), which is define as: $$FP=\cases{1,&$\text{Eta}<J$\\ \frac{1-\left| \text{Gam}\right| }{2}, &$\text{Eta}=J$\\ \frac{\left| \text{Gam}*J\...
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Plotting this piecewise function [closed]

How can I plot the following piecewise function(FB) as a function of "B" ...
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1answer
37 views

Limit of multivariate piecewise function

Let's say we have a multivariate piecewise function f[x1_,x2_]:=Piecewise[{{Sin[x1]/x1,x1>x2},{Sin[x2]/x2,x1<=x2}}] Now we want to determine the limit in f(0,...
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1answer
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How to evaluate a multidimensional NIntegral in a range where certain conditions must be satisfied by the variables

I have a function f which looks similar to this : f[a_, b_, c_] := NIntegrate[sigma[a, b, c], {a, -valueA, valueA}, {b, -valueB, valueB}, {c, -valueC, valueC}] and ...
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3answers
680 views

Using OddQ and EvenQ in piecewise functions: Buggy?

I was trying to evaluate a sum over a piecewise function, not unlike this example. However, my piecewise function needed to be defined differently for even and odd ...
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1answer
47 views

How do I introduce an assumption when defining a piecewise function?

Define m as an integer. I want to specify a Piecewise function f[x,n] that takes value ...
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2answers
79 views

IVP Piecewise ODE: Changing the Domain outside region of interest changes result dramatically

Good afternoon, I am attempting to solve the following ODE: ...
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33 views

Find edges of a piecewise curve

I have a continuous function f[x], and I want to calculate the coordinates of the discontinuities in Round[f[x]]. My code needs ...
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1answer
321 views

Conversion between Piecewise[] and Abs[] representations [duplicate]

Is there a utility in Mathematica that can convert between two representations of an expression? The simplest example I can think of is Abs[x] Which I'd like to ...
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1answer
32 views

Should be a Piecewise function, a ConditionalExpression or Indeterminate, but it is a number

I apologize in advance for the lack of focus of my question. Consider the function: f[x_, y_] := x/(x + y); f[0,0] evaluates to ...
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How do I create a piecewise function using Do[] or While[]?

The following non-linear circuit is an uncontrolled three-phase full-wave 6-pulse rectifier. The inputs are $v_{an}(t) = V_m \sin (\omega t)$, $v_{bn}(t) = V_m \sin (\omega t-120°)$ and $v_{cn}(t) = ...
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2answers
116 views

Finding the maximum of a piecewise function

I have the following piecewise function of the variable $e_f$: $$g(a,b,c,w,F,e_h,e_f)=\begin{cases} \frac{(c-a e_f) (e_f (4e_f w-a)+c)}{8 b e_f^2} & \left(e_f=e_h\land e_f>\frac{c}{a}\...
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1answer
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Piecewise function not evaluating properly

I have a simple Piecewise function that defines a square pulse: ...
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1answer
54 views

ParametricNDSolve “delayed time” error message

Issue reported to Wolfram, Inc as a possible bug in Version 12.1; CASE:4554034. When trying to solve a system of delay-differential equations with ParametricNDSolve...
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2answers
55 views

Double integration with a piecewise function gives wrong result

I am attempting to solve a double integral $$I(t) = \int_0^t dt' \int_0^{t'} dt'' f(t'')$$ of a piecewise function of the type $$f(t) = \begin{cases}1 & \text{for } 0 \leq t < a \\ -1 & \...
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How can I use Callout to label the segments of a piecewise function?

When I plot a Piecewise function, I like to put the function name above each part of the plot. I could not find a way to use ...
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1answer
63 views

How to plot a thermodynamic cycle? [duplicate]

I try to plot a thermodynamic cycle with the data displayed using the tool, "Piecewise", but in the case of isochoric and isobaric processes, Mathematica shows nothing. Could someone please tell me ...
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46 views

Piecewise function and NDSolve [duplicate]

I'm trying to solve a system of differenial equations involving a piecewise function with NDSolve. I tried to define this function using Piecewise but the kernel ...
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1answer
45 views

Understand output of Integration

Could someone help me understand the output of the following Integration in Mathematica? Specifically, (a) what is the meaning of "True"? (b) Why is the answer in two parts which seem to overlap ...
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1answer
24 views

Export data from NIntegrate and Piecewise

I use the following to calculate my Integral. ...
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1answer
70 views

TransformedRegion with piecewise function

Is it possible to use TransformedRegion with a Piecewise defined function? I tried the following, but it doesn't work and I don'...
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2answers
116 views

Best 5 segment piecewise linear fit

I'm trying to get a piecewise linear best-fit for the closing price of one of the stocks I'm interested in. The logic seems ok, and the workflow works for a straight-line (ie 2 pts, ie 1 segment) ...
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2answers
229 views

(Very) ill-behaved Piecewise Plot

I am interested in defining a function (with arguments: a symbol for a variable and a list of 6 points) that represents a quadratic interpolating spline of the points. Here is my attempt ...
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2answers
613 views

Piecewise ColorFunction for Plot3D

I want to make a 3D plot where the ColorFunction is different depending on whether the function value is positive or negative. I know how to do the following: <...
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2answers
60 views

HeavisidePi Plot

how could i change This Plot to something like this plot each two plots are concatenation of HeavisidePi The code for the first plot is : ...
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1answer
46 views

How do I combine a piecewise function within a parametric plot?

I'm trying to combine two functions together piecewise style, but nest that within a ParametricPlot function. Here's my code right now: ...
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1answer
44 views

Why does HeavisideTheta not have an implicit piecewise expansion?

The Heaviside step function implicitly expands to a piecewise function: UnitStep[t - 3] // PiecewiseExpand $$ \begin{cases} 1 & t\geq 3 \\ 0 & \text{...
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Plotting a piecewise function MRI problem

I have this M.R.I. question, and i need to plot a function with some 'a' and 'b' parameters and 't' as a variable: ...
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Solving a Piecewise ODE [closed]

I am attempting to solve a piecewise ODE. $y' = \begin{cases} -1 & \text{for $y \geq 0$}\\ 1 & \text{for $y < 0$} \end{cases}, \qquad y(0)=0, \qquad x \in [0,1]$ I have attempted solving ...
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```PiecewiseExpand``` doesn't work as expected with a recursive function

In an effort to examine this question on Math.SE, I defined the following functions ...
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24 views

Find and indicate the minimum of a piecewise function in the `Plot3D` diagram

I'm trying to indicate in my Plot3D diagram the minimum level of the dependent variable and the corresponding levels of two independent variables. More specifically,...
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1answer
53 views

Piecewise integration not giving continuous result

I'm trying to integrate a piecewise function symbolically and I'm ending up with discontinuities which is surprising since the help mentions that constants are determined to ensure continuity. If I ...
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1answer
37 views

Why do Integrate and DSolve/DSolveValue yield such complex expressions for Piecewise functions?

This code uses two different methods for integrating a very simple piecewise function but yields surprisingly complicated integrals: ...
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1answer
48 views

Using subscripted symbol affects integration — why?

Below is a sample program that shows that Integrate is giving different results depending on whether I name the variable duration1 or ...
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2answers
80 views

Graphing a Fourier Series

First off, I have created the following Fourier series for the below equation/condition: $$f(t) = \begin{cases} 0, & 0<t<1 \\ 1, & 1<t<2 \end{cases} $$ My Fourier Equation for ...
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1answer
22 views

Limiting the Domain of a Function

Currently, I am trying to plot (using Mathematica) the following function: $$f(t) = \begin{cases} 0, & 0<t<1 \\ 1, & 1<t<2 \end{cases} $$ And, to try to plot this, I did some ...
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1answer
56 views

Plot of Piecewise function is slow

While working on answer for question (here) I found out that the Plot is incredible slow for Piecewise function: Some preparations: ...
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Bad Integral evaluation for Piecewise function

I have been trying to evaluate this symbolic function: f[ρ_, R_, α_, yp0_, yp_] := R*((ρ - R*Cos[α])^2 + (R*Sin[α])^2 + (yp-yp0)^2)^(-(1/2)); Mathematica can ...
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1answer
46 views

Plotting Piecewise function?

I am facing a problem in plotting the Piecewise function. I simplified my problem to take the following form: where \[Sigma][i] are Pauli matrices. My code is: <...
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1answer
752 views

Fourier Transform plot of a piecewise function

I'm working with financial data. I used "Find Formula" to find an approximate function and then I applied FourierTransform to it. Here are the function and the Fourier Transform: ...
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3answers
83 views

count conditional items in list

I have a list of the form: {1,1, (1 if x>y, -1 if y>=x), -1} I want to count the number of 1's in the list. The output I'm looking for is something of the ...
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1answer
61 views

Forcing the fit of a nonlinear piecewise function to be continuous

I am trying to fit some data ...
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1answer
169 views

Automatic Piecewise Approximation

I would like to create the following function: It should approximate a function func[x] by piecewise polynomial interpolations, splitting the approximate function ...
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2answers
6k views

Integrating a Simple Piecewise Function

If I define f[x_]:=If[x<0,-1,1] and then integrate,say Integrate[f[x],{x,-3,7}] I get what I expect, namely 4. But ...
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3answers
678 views

Solving Stefan's solidification problem - for the case of 3 regions

This question heavily related to this question, where the case of two PDE's are solved along with a zipping condition that is a function of time. Using the link in the code I have solved this set of ...
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1answer
51 views

find intersections of 2 Piecewise Functions in ImplicitRegion

How do I combine this two parts of a Piecewise functions? I have trouble join this with || ...
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2answers
36 views

Can someone tell me what is wrong with my code? [closed]

The code I am using to make my plot is: DiscretePlot[ Piecewise[{{1/((-2)^{x + 1}), x <= 3}, {1/32, x >= 4}}], {x, 0, 10}] Also, how do I change to color ...
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0answers
39 views

Need help plotting on Mathematica simple piecewise wave function from quantum physics (Quantum Physics, Griffiths, 2.7) [closed]

On Mathematica need to plot an initial wave function defined as... Psi(x,0) = Ax when 0 <= x <= a/2 Psi(x,0) = A(a - x) when a/2 <= x <= a Here is my attempted code... ...
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1answer
68 views

How to Refine HeavisideTheta or UnitStep?

Look at the following chunk of code: Assuming[x > 0, Refine@HeavisideTheta[x]] It yields 1. However the same method does ...
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55 views

Speed up Integrate around Max/Min or Piecewise

Integrate around a convex combination of two functions containing Min or Max or ...

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