Difference between revisions of "RANK ERROR"

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Miraheze>Adám Brudzewsky
Miraheze>Marshall
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A RANK ERROR is an [[error message]] which indicates that an array had an incorrect [[rank]] for the way it was used. For example, in most APLs, [[Iota]] only accepts a [[vector]] or [[scalar]], so giving it a higher-rank array results in a RANK ERROR:
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A '''RANK ERROR''' is an [[error message]] which indicates that an array had an incorrect [[rank]] for the way it was used. For example, in most APLs, [[Iota]] only accepts a [[vector]] or [[scalar]], so giving it a higher-rank array results in a RANK ERROR:
 
<source lang=apl>
 
<source lang=apl>
 
       ⍳2 3⍴⍳6
 
       ⍳2 3⍴⍳6

Revision as of 13:29, 14 November 2019

A RANK ERROR is an error message which indicates that an array had an incorrect rank for the way it was used. For example, in most APLs, Iota only accepts a vector or scalar, so giving it a higher-rank array results in a RANK ERROR:

      2 3⍴⍳6
RANK ERROR
      2 3⍴⍳6
      

A RANK ERROR can be caused when arguments do not conform because they have differing ranks:

      (2 32) + 6
RANK ERROR: Mismatched left and right argument ranks
      (2 32)+⍳6
             

It may also be caused when an array's rank is too small for a function. Windowed Reduction is not defined on scalars:

      2 +/ 0.5
RANK ERROR
      2+/0.5
       

A RANK ERROR may be caused when argument ranks are incompatible in some other way. In languages with high-rank set functions such as Dyalog APL and J, the right argument rank must be at least the left argument rank minus one. Calling it with a matrix left argument and a scalar right argument, which has a rank two smaller, gives a RANK ERROR:

      (3 4)  1 3
RANK ERROR
      (3 4)⍳⊂1 3
            
Works in: Dyalog APL