CODEWITHSUNDEEP
matlab
user2126062
user2126062

Reputation: 111

matlab insert new row in matrix which is mapped from using mapobj

My matrix currently looks like this 

1      225   230  300   
4      333   442  678
7      798   782  128
1      248   842  482

Coloumn 1 is a series of numbers which I have mapped to another set of numbers. for example 

KeySet = (1:42)
ValueSet = (333, 222, 4444, 7778 etc etc to 42 numbers)
mapObj = containers.Map(KeySet, ValueSet)

Now I want to create a new coloumn in my original matrix coloumn 5 which will be populated from the ValueSet with reference to the mapping - so row 1 coloumn 5 will be 333 and row 2 coloumn 5 will be 7778 and so on. Its essentially a vlookup from coloumn 5 into the mapping.

It would look something like this I would guess

mat(:,5) = mapObj(mat(:,1))

Upvotes: 1

Views: 46

Answers (1)

Daniel
Daniel

Reputation: 36710

You can't query a mapobject for multiple entries at once, i would use arrayfun:

arrayfun(@(ix)mapObj(ix),mat(:,1))

In your example the key set is 1:n, if this is always the case then use an array instead of a map, it's much faster and you can index multiple entries at once.

Upvotes: 0

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