21 questions linked to/from Why do I have to put Evaluate[] here
376 views

### Plotting function lists [duplicate]

Possible Duplicate: Difference in Plot when using Evaluate vs when not using Evaluate Why do I have to put Evaluate[] here Why is ContourPlot not displaying this curve? Why is nothing (empty ...
• 1,587
1 vote
311 views

### ContourPlot not evaluating correctly [duplicate]

When I try to plot an evaluated equation with contour plot in Mathematica 9, but do so with a variable, the plot is empty, but when I input the evaluated equation itself, the ContourPlot plots ...
• 11
99 views

### How to convert a list of polynomials into a list of equations and plug into Contourplot? [duplicate]

Given a list q of polynomials (output of GroebnerBasis) in two variables I want to transform the list into a list of equations and plug it into CountourPlot. For ...
• 41
1 vote
49 views

### Plotting equations stored in a variable [duplicate]

The following produces an empty plot: eqn = x^2 + y^2 == 1; ContourPlot[eqn, {x, -1, 1}, {y, -1, 1}] Whereas the following plots a circle, as expected: ...
• 4,751
41 views

### Some confusions about Evaluate[] and HoldAll in Plot[] [duplicate]

i can't understand the outputs of the three commands in the following picture. question1: In my understanding, command one Plot[Table[a*x^2,{a,3}],{x,-3,3}] is ...
• 353
9k views

### How can I mark each of several plots with a parameter that identifies it?

I've got a two variable function that I'm plotting against one axis for a few different values of a parameter ...
• 6,458
4k views

### Why is ContourPlot not displaying this curve?

I am using the general form of a second-degree plane curve: $$Ax^2+2Bxy + Cy^2+2Dx + 2Ey + F = 0$$ I want to randomly generate plane curves of this form, so I am using ...
• 2,154
2k views

### Displaying a series obtained by evaluating a Taylor series

Description of problem I would like to use Mathematica to display the series obtained by substituting a value for $x$ in a Taylor series expansion. The terms of the series will be rational numbers, ...
• 2,197
334 views

### Cases with Alternatives failed

Consider this list of rules rules = {a -> 1, b -> 2, c -> 3} I'd like to fish some of the rules out of such a list using ...
• 8,723
684 views

### Manipulating slots in a pure function

How does one manipulate the slot numbers in a pure function? Some trick with Evaluate or Hold? I'm aiming for something along ...
• 8,480
4k views

### Why won't this graph? [closed]

I'm trying to sketch level curve for z=k for the specified values of k={-2,-1,2} of z= 4x^2 - 4x + y^2 + 2y So I changed this(...
469 views

### How to plot multiple functions from a list

I'd like to get separate plots for the functions in a list, and I'm trying the following, which doesn't work. What is the correct way to do that? ...
• 387
261 views

### Why is Evaluate[] in Plot[] not necessary in some cases?

after reading some related materials(Why do I have to put Evaluate[] here), in my understanding, BecauseAttributes[Plot] has ...
• 353
838 views

### Why won't ContourPlot accept a variable argument? [duplicate]

I have a list of linear inequalities which describe a (polygonal) region. I can use RegionPlot to visualize this region; but I'd also like to overlay this plot with ...
306 views

### Why does initialization slow down manipulate in this case?

I'm trying to manipulate a plot of function with some parameters. The function is a long expression, so I tried to put it inside the Initialization options of ...
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