Questions tagged [optional-arguments]
Tag for questions about using optional arguments in Mathematica functions.
102
questions
1
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1
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63
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Propper way of getting rid of FilterRules statements when passing options?
When passing options from a function f to a function g in the body of f one can use the <...
- 928
1
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1
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117
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Condition (/;) not working correctly on a function with optional arguments and options
I have read this post: How to avoid collision between optional arguments and options, and use Mr.Wizard's method to solve this problem. But when I add conditions to optional arguments, it seems that ...
- 306
2
votes
1
answer
48
views
Force only selected optional arguments
Is there a way to force only selected values for function argument?
For example for this function:
g[x_, y_, a_: ("b" || "c")] := Print[x, y, a]
...
- 51
1
vote
0
answers
67
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Skip middle optional arguments
Is there a way to skip some middle optional arguments?
For example for this function:
...
- 51
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0
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44
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How to have Mathematica showing a dropdown list after entering an option and the -> in a function argument [duplicate]
When I enter
Plot[Sin[x], {x, 0, 2 Pi}]
Mathematica returns, as expected, the expected Sinus wave of one period.
Plot has many, many options, when I enter:
...
- 9,327
7
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68
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Why does Longest not work on OptionsPattern?
When having a function with optional arguments and options, I frequently find myself writing something like this:
...
- 23.3k
2
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0
answers
61
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How to produce an error message for each argument?
I want to print a helpful message for every wrong input. How do you compactly implement a function with custom pattern constraints, default values and error messages for each argument separately? For ...
- 5,283
0
votes
1
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77
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Why won't Sequence work when wrapping a list of arguments for deletion with Remove?
I wrote a quick and dirty little function freshStart which does a variety of things meant to give me a nearly fresh Kernel without having to ...
- 1,787
5
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64
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1
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1
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61
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How to manually create options that can be entered as a sequence or list?
I am trying to implement custom options in my code manually, rather than using the built-in Options tools. So I have functions that look like ...
- 699
2
votes
1
answer
61
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Simplest way to check if optional parameter is omitted?
Suppose I have a function
f[x_,y___]:= (code)
and I want my code to check whether the parameter y is omitted. What's the easiest ...
- 699
1
vote
1
answer
40
views
How to create custom NIntegrate with special option behavior?
I'm trying to create a custom version of NIntegrate, called MyNIntegrate, with custom option behavior. In particular, I'd like ...
- 699
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0
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64
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How to change behavior of Echo or turn it off without removing it from code?
I wish to use Echo for output of intermediate results if an OptionValue I call ...
- 1,787
2
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2
answers
80
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Help understanding options on ContourPlot3D
I am creating some figures showing the intersection between two surfaces. I managed to get most of what I want with the following code:
...
- 29
0
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1
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75
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passing splice instructions
Consider some passing splice instructions using start,stop,step pattern
...
- 902
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1
answer
59
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Keep irrelevant variables outside function arguments
I want to define several functions of variables x,y say
...
- 515
1
vote
1
answer
74
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Default Options not working in user-defined function for SymbolName
Abstract I have a function objectName[symbol] that returns the SymbolName as both a standalone function or when nested inside ...
- 1,787
3
votes
2
answers
72
views
Setting nested optional argument with a default when unpacking from a given Head
I have a head that holds a single argument, and I want to unpack the value inside it while also assigning a symbol to the value itself, for example:
...
- 257
1
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0
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51
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String arguments break optional argument default values? [duplicate]
Following a tip in this post, I use string parameters to label my functions. For example, instead of f[x]:=x^2, I use ...
- 699
9
votes
1
answer
132
views
Why Optional in Set is not held by the HoldFirst attribute?
When evaluatingf[x_:x0] := x, x0 will be evaluated, regardless of the HoldAll attribute of <...
- 702
2
votes
1
answer
90
views
Issue using optional argument before options [duplicate]
I have a problem using optional arguments before an OptionsPattern:
...
- 30.3k
10
votes
2
answers
752
views
Define function that behaves almost identically to Mathematica function
Often I like to define my own functions that are almost exactly the same as Mathematica defined functions, apart from a few tweaks. See this question for example. I want to define them properly so ...
- 3,286
5
votes
1
answer
88
views
Why is { } interpreted as an option in my function? [closed]
I don't understand the output from:
...
- 1,094
0
votes
0
answers
58
views
Optional argument in Set Function [duplicate]
Optional arguments can be defined in SetDelayed (:=) Functions (see f1 below and here and here). However, how can one accomplish this in Set (=) Functions (see f2 and f3 below)?
...
- 1,535
2
votes
1
answer
62
views
OptionValue and OptionPattern not Changing Values
I am trying to produce a function with a few sets of arguments, one of which can accept options. However it doesn't seem to be responding to the changes that I accept.
...
user47636
0
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0
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43
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Method option of function MatrixRank
By running ??MatrixRank, I see that it has an optional argument named Method.
However, this argument is not in the ...
- 181
7
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0
answers
178
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OptionsPattern[] Vs. opt___ [closed]
Since version 6 I've been dutifully using OptionsPattern[] instead of the original opts___ for passing options to functions.
I ...
- 111
8
votes
2
answers
422
views
Are Mathematica commands always supposed to check that Method -> name is valid?
When calling a Mathematica command which accepts a Method -> name option, I always thought that if the name given is not a ...
- 108k
1
vote
1
answer
1k
views
Set absolute size of Axis or frame for a plot
I have to publish some work and it requires to meet specific criteria for the image size and plot size. 1) the Area of the figure must be fix 2) the width of the x-axis also must be fix for any plot ...
- 121
2
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0
answers
46
views
Scoping of OptionValue for inner functions in closures
Assume a function f is a closure over an inner function g. Both f and ...
- 8,259
4
votes
2
answers
106
views
How to prevent an Optional parameter from taking an OptionsPattern parameter without multiple function definitions? [duplicate]
I have function the needs to enable some Optional parameters and an OptionsPattern. The issue I am facing is that the options ...
- 39.3k
3
votes
1
answer
55
views
Using other functions' replacement rules
I have a module that uses some default options for NDSolve like so
...
- 559
1
vote
1
answer
43
views
Why doesn't OptionValue cooperate with Map? [duplicate]
Consider the following definition:
Options[f] = {a -> 1, b -> 2}
f[x_,OptionsPattern[]] := {x,OptionValue/@{a,b}}
I thought that doing something like ...
- 3,980
11
votes
1
answer
133
views
Except @ OptionsPattern[] affects OptionValue
The background
This example works as expected, small function with a special case rule:
...
Kuba♦
- 132k
-1
votes
3
answers
110
views
OptionsPattern Confusion
I want to use the whole options pattern as the argument for HTTPRequest's "Query" parameter, but I'm not sure how to use them. When I run the following code:
...
- 397
5
votes
1
answer
159
views
What is the difference between the second argument of ToString and its option FormatType?
Is there any real difference between ToString[expr, form] and ToString[expr, FormatType→form]?
In all my examples, they seem to ...
- 19k
1
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0
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63
views
What is the best way to pass on options? [duplicate]
Say I have two functions which take the same set of options, e.g.
Options[f1] = {a -> 1};
Options[f2] = {a -> 1};
Now, ...
- 2,791
4
votes
2
answers
154
views
How to define an option or an argument whose values are confined
I want to define a function whose arguments or options can only be selected in a range. For example:
...
- 73
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0
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57
views
1
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0
answers
91
views
Automatic is not always the default option
Contrary to what one might expect, specifying an option to be Automatic sometimes changes the output. For example, by default ...
- 1,724
10
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1k
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2
votes
2
answers
389
views
Anonymous Function And Optional Arguments [duplicate]
Is there a way to get an optional arguments to work in an anonymous function.
Function[{Optional@a},If[a,True,False]]
- 7,399
3
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78
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How to define a function with an optional value related to the arguments?
It's known that we can easily define a function with optional value which is not related with other arguments, but my question is how can I define a function with an optional value which is really ...
- 33
12
votes
4
answers
630
views
Optional argument that can be completely omitted?
I am writing a simple function return similar words.
Clear[similarWords]
similarWords[string_]:=Nearest[WordList[],string]
I want to add another argument ...
- 15.6k
6
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0
answers
106
views
Examples of the single dot form of Optional?
I've known of the single dot form of Optional for a while, but never had occasion to actually use it:
Are there any good examples of use cases for it other than in relation to ...
- 30.3k
2
votes
0
answers
106
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How to create a function with option that shows dropdownlist like ( for example ) Manipulate with ControlPlacement? [duplicate]
Consider the Mathematica function Manipulate where you assign the placement of the controls with the option parameter ...
- 9,327
14
votes
1
answer
258
views
Pattern matching with List and Optional
Bug introduced in 8.0.4 or earlier and persists through 11.1.1
Thank you for bringing this to our attention. I have filed a report with our developers.
Why does this
...
- 5,559
2
votes
1
answer
84
views
Is this the correct method for using optional arguments?
I've read this page but I'm still kind of confused about something. Here's a simple example function, where it simply plots a function. If you give it the ImageSize option, it should use that, but ...
- 3,002
8
votes
2
answers
108
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How to write a `HeldOptional` variant of `Optional` that does not evaluate its second argument?
How to specify optional arguments that take functional values made me wonder: Can we come up with a variant of Optional that allows to do the following:
...
- 5,559
9
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3
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