Questions tagged [piecewise]
Questions about the Piecewise function, which is represented by different expressions for different ranges of values of its independent variable.
315
questions
1
vote
1answer
95 views
Priority of nested function in Mathematica
I am facing a small problem with the nested function in Mathematica. Please take a look at the attached Code below.
...
5
votes
1answer
141 views
UnitStep vs HeavisideTheta; KroneckerDelta vs DiscreteDelta
What are the differences between these pairs of functions? In many cases, they seem to act the same. For example, both DiscreteDelta and ...
5
votes
1answer
131 views
Does Mathematica have this function implemented?
Is there a function in Mathematica that can express a piecewise function in terms of the Heaviside theta function? Say, for example, the solution to this ODE.
0
votes
2answers
269 views
2
votes
2answers
152 views
Defining a piecewise function with underlying lattice
I'm fairly new to Mathematica, and programming in general, but I'm trying to define an $n$-dimensional piecewise function, $F({\bf x})$. Properties of the function are set by an underlying lattice, ...
0
votes
1answer
144 views
FindRoot when variable is inside a piecewise function
I want to find the root of a function that has a piecewise part. This means that the value Mathematica will search will determine in which piece of the function we will be. I don't my example is the ...
2
votes
1answer
120 views
Unfamiliar output of FullSimplify [duplicate]
I got the following output of FullSimplify, when expecting to get "0".
I found no explanation of this output here.
Could you please explain, what it means? That my expression equals zero when the ...
1
vote
0answers
38 views
Unexpected behavior when copying a Piecewise expression
When I type a Piecewise function (e.g. Piecewise[{{a,0<a<1},{2a,1<a<2}}]) in mathematica notebook using ...
10
votes
7answers
2k views
How to plot a list to look like step function?
Suppose I have the following simple list.
l = {0,2,5,9,14};
I want to to make a plot that looks like the figure below.
I.e. I want to have a horizontal line ...
1
vote
2answers
217 views
2
votes
2answers
218 views
ContourPlot combined with Piecewise bug
I'm plotting a two dimensional von Mises and Tresca yield surface and got:
...
1
vote
0answers
51 views
Strange behavior of NIntegrate
I have some function f[x,y,a], where a is some parameter, defined as piecewise
f[x,y,a] = Piecewise[{{g[x,y,a], a<m[x]}, {0, True}}]
Here $m$ is some function....
3
votes
1answer
642 views
What does True mean in this case? [duplicate]
I use the following code to find the expansion for small $x$:
...
0
votes
1answer
263 views
set colours for different parts of a piecewise function's graph [duplicate]
I would like to create a graph of the piecewise function
$f(x) = \begin{cases} x + 2, & x < -1 \\ x^2, & -1 \leq x \leq 2 \\ 3, & x > 2\end{cases}$
where the changes in the ...
2
votes
0answers
84 views
I get gaps when use Plot3D combined with Piecewise [closed]
I am trying to plot a function that is Piecewise in both dimensions.
I write this
...
4
votes
1answer
101 views
Simplify integral with piecewise expression
How can I simplify this integral?
Integrate[Piecewise[{{c[x], 0 <= x <= 1/2}, {0, True}}], {x, 0, 1}]
I think it should be the same as
...
1
vote
2answers
161 views
Plotting orbit of a discontinuous map
I'm trying to plot the orbit of a two dymensional discontinuous map. Could you help me please? I tried using Piecewise, but I didn't get the result I wanted. The ...
2
votes
1answer
304 views
Force derivative of piecewise function at boundary points to be one-sided derivative
I've defined a smooth step function given as
f[x_] = Piecewise[{
{y0, x<x0-dx/2},
{y0+1/2(y1-y0)(1-Cos[Pi*x/dx]), x<x0+dx/2},
{y0, True}
}];
...
6
votes
3answers
427 views
Integrating a piecewise function with symbolic pieces
Suppose I want to compute the antiderivative of this simple function:
$$f(t)=\begin{cases}
1 & \text{if $0\le t\le t_1$,} \\
-1 & \text{if $t_1\le t\le t_2$}, \\
0 & \text{otherwise,}
\end{...
2
votes
1answer
63 views
ColorFunction makes choppy line in Plot
I'm trying to apply a ColorFunction[] to a piecewise plot. For some reason, applying the ColorFunction[] to a plot results in ...
3
votes
3answers
91 views
How to get edge values of the piecewise function if it has discontinuties
Qplot = Piecewise[{{Ray, h <= c/3},
{Ray-P, c/3 <= h <=c},
{Ray-P-q*(h-c) + X1, c <= h <= c+b},
{Ray-P-q*b + X1 + X2, c+b <= h <= c+b+a}}]
...
4
votes
1answer
90 views
Chop in Piecewise function
I'm trying to implement a complex square root with branch cut on the negative real axis; the (real part of the) second argument determines which branch to take.
...
3
votes
0answers
108 views
Simplifying Redundant Piecewise Cases
I would like to perform a summation from $1$ to $M$ of a simple piecewise function. For example,
...
1
vote
1answer
105 views
Cross-sections of a revolutionplot3D of a piece-wise function
I trying to get multiple cross-sections of a revolution plot I made from a piece-wise function.
The end goal would be to calculate integrals underneath those cross-sections.
my code looks like this:
...
2
votes
0answers
80 views
Piecewise function Syntax error only in debug mode
If I enter the following through mathematica (11.0) through UI $$\begin{cases} 1 &x \geq 0 \\ 0 &True \end{cases}$$ No error is reported.
$$\begin{cases} 1 &x \geq 0 \\ 0 &True \end{...
3
votes
0answers
105 views
PiecewiseExpand fails with min of two piecewise functions
I have two Piecewise functions that are (in this case) just the empirical CDFs of two sets of data:
...
4
votes
3answers
501 views
Most efficient way to integrate a linear piecewise function
I am having a lot of trouble integrating a simple function. Here's the context: I generate data from two distributions, and I want to calculate the overlap coefficient of representing those datasets ...
3
votes
0answers
105 views
Piecewise and ProbabilityDistribution malfunction when used together
Yesterday I opened this question, what had a happy end after all.
But when I tried to model more complex discrete random variables using Piecewise instead of ...
1
vote
2answers
87 views
Piecewise integration fail or something else?
I have a not-so-complicated piecewise cubic function, shown below as the yellow curve on the right. It's derivative is on the left; the blue lines are references. Please see the code below where I ...
3
votes
2answers
87 views
Difference in Piecewise function
I have two piecewise functions that are defined on values of [0,200].
I would like to find out the maximum difference between the two values.
The usual Max[] function does not work because all values ...
1
vote
1answer
225 views
Piecewise function created from list
I have a list of values called EDFh3. This contained values which are partitioned by 3 where it is in the format
...
1
vote
1answer
228 views
How to implement a loop inside Piecewise?
I wanna be able to use the Piecewise function such that I don't have to manually enter all the pieces. For example, say I define
f[x_]:={x,x^2,x^3}
Consider now
...
1
vote
1answer
124 views
DSolve, Simultaneous Eqns + Piece-wise + boundary and initial conditions
mathematica noobie here but could really use some help.
So I have 2 sets of equations:
1) w''''[x]=0 and
2) w''''[x]=q[x]
1) has conditions w[0]=0, w'[0]=0
2) has conditions w''[1]=0, w'''[1]=0
1) ...
3
votes
2answers
271 views
Plot of piecewise function is not bounded properly
I am trying to plot a piecewise function that gets bounded above and below a certain value (e.g).
...
0
votes
1answer
103 views
Selecting only list of function output from piecewise function output [closed]
Say I have a piecewise function:
V[m_] := Piecewise[{{(1 + m)^2, m >= 1}, {Log[m], m < 1}}]
And I input a large list of ...
0
votes
1answer
2k views
Plotting a piecewise function [closed]
I'm having trouble plotting the piecewise function below. The only way I can replicate this function is using
...
0
votes
3answers
324 views
How do I insert a circle inside another circle with Piecewise?
I need to create two circles, where one circle is inside the other using the Piecewise function. So far I have
...
1
vote
1answer
223 views
Variable Increments in a Table
I am working on a problem involving the piecewise function:
$$x^2 \quad \mbox{if } \quad x < 2$$
$$(x-3)/(\sqrt{x-2}-1) \quad \mbox{if } \quad x \geq 2$$
I am supposed to find ...
0
votes
3answers
131 views
How I can define this staircase function?
I have a function $f:[-1,1]\to\Bbb R$ defined by
$$f(x):=\begin{cases}\frac1{n+2},&x\in\left[-\frac1n,-\frac1{n+1}\right)\cup\left(\frac1{n+1},\frac1n\right]\\0,&\text{otherwise}\end{cases}\...
1
vote
3answers
67 views
Can i use PiecewiseExpand to expand If statements with function arguments?
Usually PiecewiseExpand[] is able to convert If[] statements to Piecewise functions, e.g.
<...
1
vote
1answer
120 views
Interpretation of HeavisideTheta Integration Output
I need to integrate integrals of the type
Integrate[Boole[2 k*q >= Absolute[p^2 - k^2 - q^2]], q]
where $q$, $k$, and $p$ go from $0$ to $1$.
To learn to ...
1
vote
1answer
237 views
How to write a piecewise function to take a list of {value,point} as its parameter?
I want to apply Piecewise function to a list of range and values, for example, to make
f[{{v1,r2},{v2,r2},{v3,r3},{v4,r4},...,{vn,\[Infinity]}}]
generate:
...
0
votes
0answers
172 views
Piecewise defining function, Why do i get extra 0 True? [duplicate]
I have included a picture
This happens on every Piecewise function
0
votes
0answers
162 views
Minimize integral with piecewise functions
I am not an experienced user of Mathematica.
I would like to find parameters $d1,d2,d3,e1,e2,e3$ which minimize such an integral (given $c11,c12,c13,c21,c22,c23,c31,c32,c33$):
$\int_{0}^{1}\int_{0}^{...
4
votes
3answers
183 views
Getting error message when integrating a simple piecewise function
I reviewed the following questions:
question 1 and question 2, but I need to the following integral of a piecewise function:
...
1
vote
1answer
182 views
Using Manipulate to Plot a Piecewise Function
I want to plot a piecewise function with two variables using Manipulate command, but I am having trouble with it.
The function I want to plot is profit1. (details of the code can be found below)
<...
1
vote
2answers
263 views
Calculating probability of piecewise function
I want to calculate the probability of a discrete random variable. First I defined the function:
pw = Piecewise[{{1/8, x == 1}, {2/8, x == 2}, {5/8, x == 3}}, 0];
...
3
votes
2answers
427 views
InterpolatingFunction within Piecewise gives range error?
So I have a function myfun with positive domain that I got from NDSolve and a bunch of transformations afterwards. I can plot it on its own like
...
11
votes
2answers
417 views
StreamPlot No Longer Works With Piecewise Function?
Bug introduced in 7.0.1 or earlier and persisting through 11.1
I was trying to plot a phase portrait (StreamPlot) using a piecewise (...
1
vote
1answer
109 views
Create piecewise f[x,y] from functions with intersecting domains
I have two functions f1 and f2. They have a square region in the $x-y$ plane as their domain. They might intersect, or they ...
