Array: Difference between revisions
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There is no associative access facility, of the form "what indices of A satisfy this condition", except almost: the INDEX function, which however is allowed only for CHARACTER variables. <code>L = INDEX("sometexts","text")</code> will return 5, the location of the first occasion (counting characters from one) where the second parameter exactly matches a portion of the first.
With F90 came the standardisation of many expanded facilities. Arrays can be defined with any lower bound instead of just one, as in <code>REAL A(1951:2017)</code>, and with it now possible to define compound types, there can be arrays of such aggregates. Type matching remains strict, however. There is also much greater flexibility in manipulating arrays without explicit looping. The
Similarly, F90 provides additional functions applicable to arrays; there is a TRANSPOSE, and <code>MAXLOC(A)</code> returns the index of the (first encountered?) maximum value of the array, but there is still no extension for INDEX. However, a new statement provides some more associative processing, as in <code>WHERE(A > 0) A = 1/A</code> for a simple case.
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