Questions tagged [concatenation]
Questions on how to concatenate/join/merge lists/arrays of symbols/numbers/strings/etc. to obtain a given form of the output.
23
questions
17
votes
3answers
1k views
Simple way to concatenate Dataset columns
Consider these two datasets:
d1 = Transpose@Dataset[<|"a" -> Range[5]|>];
d2 = Transpose@Dataset[<|"b" -> Range[5, 1, -1]|>];
{d1, d2}
What's ...
10
votes
3answers
1k views
How to build a matrix from a set of vectors and other matrices using ArrayFlatten
I want to build a 6 by 3 matrix, from the following: one vector is 3 by 1, then a matrix, which is 3 by 2. These will go to the top 3 rows. Now the bottom 3 rows, I'll have 3 vectors each is 3 by 1. ...
9
votes
2answers
896 views
How to name a variable with the value of another variable?
A simple but very important (at least for me) question.
In some languages for defining a variable, for example, we can do:
i=10
"d"&i=30
So I have defined the variable d10, and...
d10=30
...
6
votes
4answers
725 views
Concatenating strings, unevaluated expressions and evaluated expressions/values
Maybe this is something very simple to some of you. Anyway, I think this can be useful to many others like me.
I would like to build an output that involves strings, unevaluated expressions and ...
6
votes
3answers
399 views
Convert a list to an integer
How can we convert a list to an integer correctly?
{5, 22, 4, 5} -> 52245?
When I use the command FromDigits in Mathematica
...
6
votes
3answers
310 views
How to 'merge' a list like FromDigits, but with a mixture of numbers and symbols?
How do I go from {C,4,G,5,S,7} to C4G5S7
6
votes
3answers
2k views
how to concatenate a list of a list of strings
I have two lists of lists, La and Lb that I want to concatenate so that every element of a list n in La is concatenated with the ...
5
votes
7answers
4k views
Getting a String from a list of strings
Is there a way to write down Mathematica with a string such as:
{"M","a","t","h","e","m","a","t","i","c","a"}?
5
votes
2answers
7k views
Joining Together Strings and variables [closed]
I am trying to join together strings and variables as part of formatting the output of my code. For example how do I print the line "5 trees" where the number 5 is a variable n that could be changing. ...
5
votes
3answers
411 views
List of the combinations of more lists via permutations
I would like to generate a list of all the possible combinations of two lists. As for instance, given L=3;
list={0,1,2};
I would like to obtain the list
{{0,...
3
votes
3answers
296 views
How to join many tables side by side?
I have function for table $t$
t[n_] := Table[i*n, {i, 1, 3}];
For example t[1]=(1, 2, 3), t[2]=(2, 4, 6), and t[3]=(3, 6, 9)
To join $n=3$ tables side by side ...
3
votes
2answers
105 views
Obtaining all possible ways to concatenate matrices
With Prepend we can add a line to all matrices in a set, like this:
...
3
votes
1answer
80 views
What's the easiest way to combine specific columns of two matrices?
given matrices
A = {{3, 10, 10, 5.`}, {4, 10, 10, 6.`}, {5, 10, 10, 7.`}}
B = {{6, 10, 10, 5.`}, {7, 10, 10, 6.`}, {8, 10, 10, 7.`}}
how can i get a matrix which ...
3
votes
1answer
96 views
Merge neighbour Lists in List
I think the following problem is a good exercise. In a List of Lists, merge lists which define neighbour intervals: for example,
...
2
votes
5answers
811 views
How to switch from array to string?
Considering we have an array:
a = {2/3, 4/5, 9/7, 3/7, 1/7, 1/9};
How can I get this to be:
"2/3 4/5 9/7 3/7 1/7 1/9"
...
2
votes
5answers
96 views
Build a new flat list from a mix of part items and part spans
I want to modify a list of table row by adding an extra column. For that I Map the data with a pure function that evluate the new column value from exisiting one ...
2
votes
1answer
113 views
How to joint symbolic expressions together [duplicate]
I want to joint symbolic expressions together to create a another symbolic expressions.
one way to do that is as follows:
...
2
votes
2answers
175 views
1
vote
2answers
71 views
Building other matrices from these ones
First of all, I want to know if it is possible to make a constraint in a set of matrices that I have to obtain a subset. For example, if I have a set of square matrices ...
1
vote
1answer
50 views
How to use 'Join' and '& /@' : combining all .csv files in a directory into a single .csv file automatically
I would like to import all .csv files in a directory and combine them into a single file using Join. I can do this manually but when I try to automate it using <...
1
vote
0answers
45 views
How to define a symbollic matrix with variables and numbers
Newbie here.
I want to define a (user-defined)function to return symmetric matrices, as I need to define quite a few tensors. I am able to do this using strings. But I need the matrix entries to be ...
0
votes
1answer
76 views
How to use Strings and Functions With Conditions
Very new to Mathematica so this might be really simple.
I have the function
pow[x_,r_]:= x^r
where r is rational due to
...
0
votes
2answers
414 views
How to concatenate functions and strings
I have
f[x_]=Log[1+x]
g[x_]=TraditionalForm[Series[f[x], {x, 0, 4}]]
Is there a way to get the answer to print out as
...
