Questions tagged [implicit]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1
vote
1answer
60 views

Composition of implicit functions

Let me explain what i have been doing so far. So I want to find an numerical solution or at least a grafic solution to this equation: ...
1
vote
0answers
43 views

DSolve: lack of implicit option (unlike Maple's dsolve built-in option)

I am working with the book 'Differential Equations for Engineers' (Cambridge University Press). The author dedicates one chapter of the book in solving ODEs with Maple. The book was published in 2010. ...
1
vote
0answers
51 views

How do I plot two normalized variables with one varying parameter as a 2d plot or a contour plot?

I'm trying to replicate a plot that has both (x,y) normalized variables, I've tried using Evaluate and Contourplot with no success. I have set Rn=20, but it should be another variable. Where Fn=fs/fr, ...
1
vote
1answer
52 views

Improve performance of evaluating over an implicit region

Consider the following implicit region: ...
0
votes
2answers
61 views

Implicit differentiation such that I an numerically solve an equation [closed]

If I have some function: N(t) = N0e^(bt) where b is a function of N(t). How do i calculate dN/dt? It gives me a recursion warning since it's just caught in a loop of substituting in N(t) into b over ...
4
votes
3answers
226 views

Plot involving an implicit function

I'm trying to make a plot that depends on an implicit function. This example illustrates the problem: plot $c=2l +n$ in the $c \times l$ axes, where $n$ is implicitly determined by $n^5+ 2n = c^2$. ...
3
votes
2answers
164 views

Solving the Shifted Neutral Axis Problem

Problem Description: In solving the "Shifted Neutral Axis" method for the stress distribution of a vertical steel vessel supported on a concrete foundation, we can derive the following ...
0
votes
2answers
74 views

Plot implicit polar equation streamlines

I'm trying to plot streamlines of Stokes solution to an sphere, the expression of streamlines is I've seen similar questions before and this what I have tried As you can see, a=1, U=1, but it seems ...
2
votes
0answers
75 views

Large system of implicit differential equations

We are trying to solve a large system of implicit system of differential equations for complex variables $\boldsymbol{\alpha}\left(t\right)$ and $\boldsymbol{\lambda}\left(t\right)$. System consists ...
0
votes
0answers
24 views

Domain of definition for the following variables: is it possible to derive in Mathematica?

Consider 4 4-vectors $$ P_{0} = (E_{0},0,0,\sqrt{E_{0}^{2}-m_{0}^{2}}), \quad P_{i} = (E_{i},p_{i}s(\theta_{i})c(\phi_{i}),p_{i}s(\phi_{i})s(\theta_{i}),p_{i}c(\theta_{i})), $$ with $c \equiv \cos, s \...
3
votes
1answer
224 views

Solve transcendental equation involving a built-in function [closed]

How can I solve an equation of the following form? $$x = 10+\mathrm{\mathbf{PrimePi}[x]}$$ where $x$ is an integer. I am using Solve but am getting the following ...
1
vote
2answers
68 views

Interval arithmetic and implicit function inside test

I has implicit function and square region. I need to check this region for presence of part of curve, with interval arithmetic only. My attempt: ...
3
votes
1answer
181 views

Can we convert any parametric equation to implicit form?

The Archimedes spiral equation in parametric form: fx[t_] := Cos[t]*t; fy[t_] := Sin[t]*t; How can it be converted to implicit form? Is there a general method ...
9
votes
1answer
642 views

How can I find a parametric equation for an implicit surface?

I need a parametric equation for the Taubin heart surface, which is defined in implicit form. I asked a similar question in math branch, but didn't get an answer. This is the implicit form: $$\\\...
0
votes
1answer
27 views

How to plot the absolute values of the solutions to a parametric equation versus the parameter?

Mathematical formulation of my problem: Let $\Theta\subset\Bbb R$ be an interval. For each $\theta\in\Theta$ let $f_\theta: \Bbb C\to\Bbb C$ be some function and $z_{\theta,1},\ldots,z_{\theta,n(\...
0
votes
1answer
95 views

Solve implicit equations, input and plot the solution in a different equation

I have two implicitly defined variables, $\sigma_D$ and $\sigma_M$ one of which is a function of the parameter $v$. In particular, $\sigma_D = F(\sigma_D,v)$ where $F(\sigma_D,v)=0$ if $ c_D < -0....
1
vote
1answer
148 views

How to get the implicit solution of this PDE (Maple can but I don't manage with mathematica)?

I asked this question about the analytical solution of the PDE: $$\partial_t c=\partial_x((c-a)(c-b)\partial_xc) $$ And I was given the answer that Maple gives the following implicit form as a ...
0
votes
1answer
41 views

How can I get paired coordinates from the implicite function?

I have equation E^y = x. How can I use Mathematica to solve all of "y" from the desired "x" value. For example, I want to solve for "y" from x = 0.5 , 1 , 1.5 , 2 , .... , 9.5 , 10. The solution ...
2
votes
2answers
111 views

Solve implicit equations and plot solutions as parameter changes

I have the following two implicit equations that are functions of a parameter $f \in (.5,1]$. I would like to solve these two equations (i.e get $\sigma_D$ and $\sigma_M$) for different $f$ values and ...
1
vote
1answer
68 views

Determine inverse function with Gröbner basis

I am trying to generalize a way to invert a function using Gröbner basis. My functions are defined in the following form: ...
0
votes
1answer
214 views

Implicit Function Theorem

I think I am stuck here right now: The exercise is to use implicit differentiation to determine y' considering the following equation: I managed to do this with: ...
8
votes
2answers
728 views

How to plot a surface from a system of equations? [duplicate]

It seems like a natural thing to do, however I can't seem to find anything on the docs nor here on SE. What I'd like to plot is the locus of solutions to a system of (polynomial) equations, e.g. $$\...
0
votes
0answers
55 views

How to Solve a Differential Equation System Depending on Variable Solved in an Implicit Function?

I have an ordinary differential equation system need to be solved by using Mathematica. $\frac{dk(t)}{dt}=((1-\kappa(t))k(t))^{\alpha}(1-\frac{\kappa(t)}{\kappa(t)+\frac{1-\alpha}{\alpha}\frac{\eta}{\...
5
votes
2answers
158 views

Holes in ElementMesh with ToElementMesh of ImplicitRegion

I am trying to plot a function in a region below a level curve of the function and within a cell. I have been doing this by calculating an ElementMesh using ...
3
votes
2answers
219 views

Plot implicit region in 3D not working

I'm having troubles plotting an implicit region R (the full expression will be given at the end of this message for sake of readability). This implicit region R is defined by both inequalities and ...
2
votes
2answers
162 views

Multivariate series for approximating implicit system

I'm trying to approximate the solution of an implicit set of equations by means of a Taylor series. I have managed to do so for a solution expressed in terms of a single independent variable, by using ...
0
votes
0answers
100 views

Implicit derivative of set of equations

I have an equation and I want to take its derivative with respect to two variables. However, it contains some parameters which need to solve them together to find them (Pn, omega, gamma). These ...
2
votes
4answers
134 views

Printing values of y for a range of x for an implicit function f(x,y)

I want to print the values of y for a range of x for an implicit function f(x,y). My equation is f(x,y)=x^2+y^2+2. The range of x is (2,10). I want the corresponding values of y.
1
vote
1answer
131 views

Implicit and Parametric Plot

I am trying to graph the partials of two equations with respect to t, with both equations being implicit. I know I should be getting ellipses with the x-axis as the major axis. ...
8
votes
1answer
186 views

ElementMesh from ImplicitRegion cuts corners of region

I'm trying to define a region within a cell and below a level set of a function using ImplicitRegion and ToElementMesh. Here I ...
0
votes
2answers
145 views

How to compare ImplicitRegion with empty region?

I have the following function using ImplicitRegion: ...
0
votes
1answer
233 views

How to ContourPlot a two variables (x,y) implicit function with y normalized?

I am trying to use ContourPlot to plot an implicit function. Now I have two variables (x,y) implicit function: ...
2
votes
2answers
68 views

Plot f(x,g(x)) where u(x,g(x))=0 can not be solved explicitly

Suppose $u(x,g(x))=0$ can not be solved explicitly for $g(x)$. I need to plot $f(x,g(x))$. How can this be done? An example: $\frac{1}{\log y}=y-x$ for $x\ge 1$ has a solution for $y$, but can not be ...
2
votes
2answers
78 views

Incorrect implicit region for function that indexes or sorts a list

I'm having trouble creating a region with ImplicitRegion. In general, I first limit the region to be within a Parallelogram. <...
0
votes
0answers
66 views

Mathematica giving incorrect result for implicit equation $x^{\frac{2}{3}} + y^{\frac{2}{3}} = 1$? [duplicate]

When I type the following implicit equation into Mathematica I only get 'one quarter' of what the resulting plot should look like, i.e., I only get the upper-right quadrant. ...
1
vote
2answers
277 views

3D plot over an implicit region gives no answer

I have a function(X,Y) which I would like to plot over an implicit region. ...
3
votes
0answers
133 views

Errors Using FindFit and FindRoot

I'm trying to fit the following equation to data: where and x and y are the dimensionless variables x=V/Vr and y=Ir/(2*I0). n=1 and I'm trying to find Vr and R. The blue is an example of the curve ...
1
vote
0answers
26 views

Implicit Root and RegionPlot [duplicate]

Here is my problem: I am trying to RegionPlot; however, I have an implicit root. I tried the following code but it generates an error and does not paint the region I know for sure exits: ""The ...
0
votes
0answers
113 views

IterationSafetyFactor error in NDSolve

I am solving a set of 4 coupled, nonlinear ODEs using ImplicitRungeKutta in NDSolve. I am running the solutions over many different initial conditions, and for about 20% of solutions, I get the error ...
4
votes
2answers
197 views

Is there a Bug in Mathematica 11.1 with RegionCentroid?

Bug introduced in 11.1 and fixed in 11.2.0 I solved for the centroid of $x^2+y^2+\sin(4x)+\sin(4y)=4$ ...
7
votes
3answers
327 views

How to Discretize the Following Region Using Reasonable Bounds?

I want to accurately discretize the implicit equation $x^2+x+y^2+\sin(4xy)+\sin(3xy)=3.9$. To get the whole discretized shape, I'm forced to use oversized bounds ...
1
vote
1answer
310 views

Fitting to the implicit function

I already asked questions about this issue here but there have been some changes that I want to ask a new question. My data is : ...
-1
votes
1answer
93 views

How can all the data points be extracted from a graph of an implicit function which is plotted using Contourplot? [closed]

I have a plot of an implicit function. I would like to extract all the data points from the graph. The plot is done using contourplot and cannot be plot with plot command.
1
vote
2answers
71 views

Degenerate graph using ContourPlot

I have this code Manipulate[ContourPlot[x^2 (z + 1) - (x + 1)^2 (z - 3 x^3) == 0, {x, -v, v}, {z, -w, w}], {v, 1, 50}, {w, 1, 50}] to interactively make zoom in ...
2
votes
0answers
196 views

Fitting to an implicit function

I am trying to fit a data ...
7
votes
1answer
311 views

Length of a curve parallel to a spline

I have constructed a BSplineFunction through a set of random points: ...
9
votes
0answers
96 views

How can I plot a region parametrized by another region?

I am trying to learn how to describe and plot a 2D-region for $x_1$ and $x_2$ based on / parametrized by another 2D-region for $v_1$ and $v_2$. In the following example, the region ...
0
votes
1answer
144 views

Derivative of an Implicit Function

So I'm having a bit of an issue in trying to take the derivative of an implicit function. The problem I'm trying to solve is this: f(t,y(t)) = y' = e^(t-y) Where ...
5
votes
4answers
740 views

How to view an ImplicitRegion defined by an equality?

Bug introduced in 10.4 and fixed in 11.0 I type l = 3 r = ImplicitRegion[(x^2 + y^2)^3 == l *x^2* y^2, {x, y}]; RegionPlot[r] and I obtain How could I ...
1
vote
1answer
610 views

Solve implicit complicated equation

I have to solve the following implicit equation: ...