Questions about the use of built-in Mathematica functions, including pure functions.

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1
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2answers
58 views

How to make function accept list of rules as an argument?

Considering the list of rules: r= {"a" -> "1", "b" -> "2", "c" -> 3, d -> 231, "e" -> 1.25}; I want to have a function ...
0
votes
0answers
46 views

How to make Piecewise continuous [duplicate]

I have a function defined by its slope in a continuous sequence of intervals, e.g. ...
11
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0answers
135 views

Default behaviour of Hash[expr] and hashing in different versions of Mathematica

In different versions of Mathematica, Wolfram silently changed the behaviour of Hash when the algorithm is not specified explicitly ...
8
votes
0answers
126 views

More Ticks::ticks errors in AbsoluteOptions in v10

Bug introduced in 10.0.0 . Bug remains as of 10.1 While the specific bug affecting Plot described in AbsoluteOptions prints error messages in V10 has been fixed ...
0
votes
1answer
67 views

Codes for the derivative of a random polynomials

Good day! Please, I need some help here, I used this codes ...
1
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3answers
126 views

Simplify a composition of functions

How do I make Mathematica simplify, for example, (1-#&)@*(1-#&) into #&? ...
1
vote
2answers
122 views

Minimizing the largest difference between two functions

I have two functions defined on the same domain, $f(x)$ and $g(x)$ where $x$ is in $(0,1)$: f[x_] := (-1 + x) Log[1 - x] - x Log[x] g[x_] := Log[1 + 2 (-1 + x) x] ...
0
votes
3answers
119 views

How to define a function

How can I define a function which depends on a function of x? Something like this f[u[x]_,u[x]']= u[x]' + a [x] u[x] +b[x] I think I wasn't enaugh clear. If I ...
3
votes
2answers
127 views

What's real analogue for FromDigits?

FromDigits only works for integer strings. What's its real-number analogue?
2
votes
2answers
60 views

How to apply list of values to a list of functions

I have the following: first= {1+a,2+a,3+a,4+a} and a list t={0,1,2,3} I want to evaluate the first element of "first" at ...
1
vote
1answer
34 views

Calculate the partial vapor pressures of a variable at xB = 0.75 based on the interpolation functions of the data

I'm having troubles in solving an exercise for an assignment in my Chemistry course. Talking about interpolations, I've already have a graph but I need to:(c) Calculate the partial vapor pressures of ...
0
votes
3answers
79 views

Using Solve to obtain a constant so that f(x) is continuous at x=2

I need to solve for c such that the function is continuous at x=2. How do I do this automatically? I have expressions for ...
2
votes
1answer
69 views

How to package a function for export?

I often post code for functions on Stack-Exchange, and then later find that they are unexecutable - that people can't use them because I mistakenly omitted some private functions or values that are ...
5
votes
1answer
67 views

Using a progress bar in a functional expression

If we have a procedural construct like a Do loop or Table, it is straightforward to make a progress bar to indicate the percent ...
1
vote
1answer
88 views

What are the terms of the sequence generated by Zeta(3s)/Zeta(s)?

The LiouvilleLambda function has Dirichlet generating function of Zeta[2s]/Zeta[s]. I am curious about an analogous function with Dirichlet generating function of Zeta[3s]/Zeta[s]. Can Mathematica ...
0
votes
1answer
76 views

how to download using weather data function many proporties exactly.

how to download using weather data function many proporties exactly. Example WeatherData["WMO44292", "Humidity", "Pressure", "Temperature", \ {{2005, 1, 1, 0, 0}, {2015, 1, 1, 0, 0}}] .
1
vote
2answers
58 views

NotebookWrite in EvaluationBox forces Input CellStyle

There is a promissing new function EvaluationBox[] and a nice last example in documentation section for it: ...
1
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1answer
37 views

How to change time zone for all outputs? [closed]

How to change the time zone in Mathematica for all functions returning a date or time?
3
votes
1answer
47 views

How should I define functions that distribute over Plus?

I have a linear function which also follows the chain rule (it is a derivation), so I defined it recursively, following a Wolfram tutorial (which I've misplaced) and other related answers: ...
1
vote
1answer
66 views

Working with derivative of conjugate of a complex number

I have a complex function, lets say $g(x)$. I want to take its and its conjugate's derivative. I need the solution of derivative which must be symbolically and computationally efficient. Lets take an ...
2
votes
1answer
178 views

Weierstrass function

I am trying to create plot of the Weierstrass function in Mathematica. I wonder if it's possible, when I define this function as ...
1
vote
1answer
61 views

FunctionDomain doesn't work with If

When I call FunctionDomain for function defined by a formula with If, for example ...
1
vote
0answers
45 views

How to simplify an expression with a radical sign nesting in a radical sign

Is there a function can simplify an expression with a radical sign nesting in a radical sign in Mathematica? I use V9. RatDenmon is a function that can ...
0
votes
2answers
82 views

Function with condition

I am starting my adventure with Mathematica. I would like to know if is there possibility to create function described by formula for example f(x):=1+2^n where 2^n < x. I have problem with this ...
1
vote
1answer
39 views

Tooltip : Mapping list of Tooltip values to list of functions while plotting

How is it possible to map a list of Tooltip values to the functions being plotted? For example: Assume, f1[x], f2[x], f3[x]... are functions defined. {t1, t2, t3, ...} are the list of tool-tips to ...
1
vote
2answers
48 views

Problem with Replace function [closed]

I recently started using Mathematica. I'm not able to understand my mistake. I'm trying to implement the Frangi vesselness for the enanchement of vessels in biomedical images. I wrote these functions: ...
0
votes
1answer
34 views

Generating comma separated input for LCM [duplicate]

I would like to calculate the Least Common Multiple of the 100 first numbers. I've tried with LCM[Table[i, {i, 10}]] But it produces a list instead of the right ...
0
votes
0answers
38 views

Piecewise function output response interpretation

Piecewise[{{t^2, t <= 0}, {t, t >= 0}}] Outputs: t^2 t <= 0 t t >= 0 0 True What does the last line of output 0 True mean? Sometimes it ...
0
votes
1answer
81 views

Simultaneously fitting two data sets to two functions is too slow [closed]

I have to fit two data sets to two functions(eps1,eps2) with same parameters (w0,f,g) Initially, I know only one function ...
1
vote
2answers
95 views

Evaluate a list

I have a function $f(x_1,\cdots,x_n)$ that takes $n$ arguments, and I would like to evaluate it using a list of lists $\lbrace\lbrace x_1,\cdots,x_n \rbrace,\cdots,\lbrace x_1',\cdots,x_n' ...
1
vote
1answer
41 views

Defining functions that depend upon other functions which depend upon other functions and so on

The problem is that I have to evaluate functions, that take output from previous functions, and combine them to form new functions, and do some operations and evaluate the value at new function. But, ...
0
votes
1answer
51 views

Does Mathematica always return a rational number in its simplified form? [closed]

If I enter: 1/RandomInteger[10^200]+1/RandomInteger[10^200] I get (instantly) an exact fraction. Is this fraction in simplified (reduced) form? In other words is ...
0
votes
1answer
44 views

FindRoot over a function with some constant variables

I would like to perform the FindRoot command over the function func. Suppose: ...
7
votes
2answers
646 views

How to programmatically covert a function-like rule to a pure function?

Is there a programmatic way to convert a Mathematica rule that acts like a typical mathematical function of one variable into the equivalent pure function? For example, the code should convert ...
2
votes
1answer
44 views

How do I make Mathematica nest argument changes?

I want something like Nest[f,x,n], but what where f is an argument change like a pushforward and x[t] is a function, for example, symbolically, and not in any sort of code: $$ F{x[t]} \equiv x[2t + ...
1
vote
1answer
102 views

Quantum Physics question [closed]

I'm not sure if anyone here would be able to help me. But if you know a more appropriate place where I could ask for help, please let me know. So here's the question: And here's my attempt at ...
3
votes
1answer
82 views

Why is left NumberPadding always applied in NumberForm?

I would like to display numbers like 9.0001 and 10.0001 in the fixed-width form of xx.xxxx. ...
17
votes
2answers
295 views

Why doesn't a Composition[] hold its arguments and what can be done about it?

Now that Composition (also RightComposition) has shorthand syntax I am more inclined to use it, however what I feel should be ...
13
votes
1answer
188 views

Why won't SparseArray let me store values with the head List?

When you attempt to define a SparseArray with elements that have the head List it complains: ...
5
votes
1answer
121 views

Why do functions defined with SetDelayed and Function behave differently in callbacks?

It seems to me that functions defined using a simple pattern and SetDelayed (the usual way to define a "function") should be equivalent in all respects to functions ...
0
votes
0answers
35 views

How can I get the covariance result cumulatively?

I am trying to derive the covariance results for n x 4 matrix where n is an arbitrary number. I am trying to derive the covariance for each row cumulatively. For example, I am trying to derive the ...
-2
votes
1answer
63 views

plot sum of two function

I am trying to illustrate sum of functions. I have one function x*x - 8*x + 7 and another Log[2*x + 4.5] I understand that I ...
6
votes
2answers
179 views

Built in function without Attributes Listable works as if it has Attributes Listable

Can Built-in function works as if it has Attributes Listable even if it doesn't have that ...
13
votes
1answer
173 views

Major slowdown when using a ColorFunction with more than one named scheme

Earlier Kuba noted a major slowdown with code Simon Woods posted. Here is a simplified example. First a color function using two different named gradient schemes: ...
1
vote
4answers
64 views

NestWhileList, control to show the second sequence

For example,each number will end up with 89 or 1, however , How can I generate a sequence with two sub sequence. f[n_] := IntegerDigits[n]^2 // Total One sub ...
17
votes
2answers
1k views

Sum or Product with Exclusions

Is there a built-in feature for handling things like: $$\sum_{\substack{i=0\\i\ne j}}^n\frac{a-a_i}{a_i-a_j}$$ and $$\prod_{\substack{i=0\\i\ne j}}^n\frac{a-a_i}{a_i-a_j}$$ or should I work out some ...
3
votes
1answer
135 views

Creating the Nabla operator as a operator

How can I define the nabla-operator as a an operator, acting on everything to the right of the operator! Also taking \[Del]^2 would give the second derivivates. I wish to be able to write ...
1
vote
1answer
47 views

little problem of Thread, List head of second argument

Thread[f[{a, b, c}, 0]] (* {f[a,0],f[b,0],f[c,0]} *) Thread[f[{a, b, c}, pp[0]]] (* {f[a,pp[0]],f[b,pp[0]],f[c,pp[0]]} *) Howerver, the head of pp ...