Questions tagged [piecewise]
Questions about the Piecewise function, which is represented by different expressions for different ranges of values of its independent variable.
378
questions
1
vote
2answers
58 views
How to plot HeavisideTheta with y=0.5 at x=0, and similar piecewise functions
How does one plot piecewise functions, with the ability to plot individual points along with open points to clearly show how values are defined at discontinuities?
Example:
Image Credit
with the ...
2
votes
0answers
48 views
How to get Integrate to determine units
In a similar fashion to the question asked here, I am having trouble trying to get Integrate to correctly determine the units of the integrand:
Here I have plugged in specific values into the general ...
0
votes
0answers
34 views
Piecewise function inside ProbabilityDistribution causing errors
I'm using a complicated Piecewise function to create a probability distribution and draw random points from it.
...
1
vote
2answers
59 views
How to take limits in Fourier series?
I have a Fourier series which produces an impulse train of period j+1. In principle, it is given by
...
1
vote
1answer
68 views
Continuity and derivability of a multivariable function at a specific point
I have this function:
f = Sqrt(Abs(x^2 - x*y))
So, how can I prove that it is derivable and/or continue in a point, like (0,0)?
1
vote
1answer
28 views
Plotting an iterated piecewise function with endogenous nodes
I am trying to plot a piecewise function that I can define recursively, where the nodes are endogenous as well. Basically, $f(l)=a^{t}$ when $l \in \left( \frac{\mu}{\alpha^{t-1}(1-\alpha)+\mu(1-\...
0
votes
1answer
52 views
Error in drawing a Piecewise function!
I want to plot the piecewise function (FP), which is define as:
$$FP=\cases{1,&$\text{Eta}<J$\\
\frac{1-\left| \text{Gam}\right| }{2}, &$\text{Eta}=J$\\
\frac{\left| \text{Gam}*J\...
2
votes
1answer
48 views
Limit of multivariate piecewise function
Let's say we have a multivariate piecewise function
f[x1_,x2_]:=Piecewise[{{Sin[x1]/x1,x1>x2},{Sin[x2]/x2,x1<=x2}}]
Now we want to determine the limit in f(0,...
1
vote
1answer
53 views
How to evaluate a multidimensional NIntegral in a range where certain conditions must be satisfied by the variables
I have a function f which looks similar to this :
f[a_, b_, c_] := NIntegrate[sigma[a, b, c], {a, -valueA, valueA}, {b, -valueB, valueB}, {c, -valueC, valueC}]
and ...
0
votes
1answer
49 views
How do I introduce an assumption when defining a piecewise function?
Define m as an integer. I want to specify a Piecewise function f[x,n] that takes value ...
1
vote
0answers
34 views
Find edges of a piecewise curve
I have a continuous function f[x], and I want to calculate the coordinates of the discontinuities in Round[f[x]]. My code needs ...
1
vote
1answer
33 views
Should be a Piecewise function, a ConditionalExpression or Indeterminate, but it is a number
I apologize in advance for the lack of focus of my question. Consider the function:
f[x_, y_] := x/(x + y);
f[0,0] evaluates to ...
2
votes
0answers
87 views
How do I create a piecewise function using Do[] or While[]?
The following non-linear circuit is an uncontrolled three-phase full-wave 6-pulse rectifier. The inputs are $v_{an}(t) = V_m \sin (\omega t)$, $v_{bn}(t) = V_m \sin (\omega t-120Ā°)$ and $v_{cn}(t) = ...
1
vote
2answers
128 views
Finding the maximum of a piecewise function
I have the following piecewise function of the variable $e_f$:
$$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}\...
5
votes
1answer
53 views
Piecewise function not evaluating properly
I have a simple Piecewise function that defines a square pulse:
...
1
vote
1answer
56 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...
2
votes
2answers
59 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
$$f(t) = \begin{cases}1 & \text{for } 0 \leq t < a \\ -1 & \...
1
vote
1answer
66 views
How to plot a thermodynamic cycle? [duplicate]
I try to plot a thermodynamic cycle with the data displayed using the tool, "Piecewise", but in the case of isochoric and isobaric processes, Mathematica shows nothing. Could someone please tell me ...
0
votes
0answers
46 views
Piecewise function and NDSolve [duplicate]
I'm trying to solve a system of differenial equations involving a piecewise function with NDSolve. I tried to define this function using Piecewise but the kernel ...
0
votes
1answer
46 views
Understand output of Integration
Could someone help me understand the output of the following Integration in Mathematica?
Specifically,
(a) what is the meaning of "True"?
(b) Why is the answer in two parts which seem to overlap ...
0
votes
1answer
27 views
6
votes
2answers
124 views
Best 5 segment piecewise linear fit
I'm trying to get a piecewise linear best-fit for the closing price of one of the stocks I'm interested in. The logic seems ok, and the workflow works for a straight-line (ie 2 pts, ie 1 segment) ...
3
votes
2answers
64 views
HeavisidePi Plot
how could i change This Plot
to something like this plot
each two plots are concatenation of HeavisidePi
The code for the first plot is :
...
2
votes
1answer
45 views
Why does HeavisideTheta not have an implicit piecewise expansion?
The Heaviside step function implicitly expands to a piecewise function:
UnitStep[t - 3] // PiecewiseExpand
$$ \begin{cases} 1 & t\geq 3 \\ 0 & \text{...
4
votes
1answer
71 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'...
0
votes
0answers
33 views
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:
...
1
vote
0answers
30 views
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 ...
1
vote
0answers
21 views
```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
...
0
votes
0answers
25 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,...
0
votes
1answer
50 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 ...
0
votes
1answer
40 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:
...
2
votes
1answer
56 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 ...
1
vote
2answers
125 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 ...
0
votes
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 ...
0
votes
0answers
40 views
Bad Integral evaluation for Piecewise function
I have been trying to evaluate this symbolic function:
f[Ļ_, R_, Ī±_, yp0_, yp_] := R*((Ļ - R*Cos[Ī±])^2 + (R*Sin[Ī±])^2 + (yp-yp0)^2)^(-(1/2));
Mathematica can ...
2
votes
1answer
62 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:
...
0
votes
1answer
49 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:
<...
0
votes
1answer
53 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:
...
3
votes
3answers
99 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 ...
2
votes
1answer
67 views
3
votes
2answers
81 views
IVP Piecewise ODE: Changing the Domain outside region of interest changes result dramatically
Good afternoon,
I am attempting to solve the following ODE:
...
1
vote
1answer
55 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 ||
...
1
vote
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 ...
1
vote
0answers
49 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...
...
3
votes
1answer
70 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 ...
1
vote
0answers
59 views
Speed up Integrate around Max/Min or Piecewise
Integrate around a convex combination of two functions containing Min or Max or ...
6
votes
0answers
62 views
0
votes
2answers
77 views
how to rewrite conditions as conditions&& True
I have a result comes from Reduce
a <= -2 || (1 < a < 2 && (x >= 1/3 (4 + 4 a))) || a >= 2
it has a ...
1
vote
1answer
45 views
Need help understanding the function in linked answer (that symbolically inverts a piecewise function)
This Answer provides the following code
...
0
votes
0answers
91 views
Using NDSolve and PieceWise for boundary conditions for coupled PDEs
I've decided to try and use PieceWise in my boundary conditions for my 4 coupled PDEs, but it doesn't seem to work out nicely. I'm receiving the error:
NDSolve::overdet: There are fewer dependent ...
