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Full Discussion: i have no understanding of how to write an array or use one, please help!
Homework and Emergencies Homework & Coursework Questions i have no understanding of how to write an array or use one, please help! Post 302463298 by jim mcnamara on Saturday 16th of October 2010 09:26:15 PM
Old 10-16-2010
1. declare -a [arrayvariablename] is optional, but good practice
So:
Code:
declare -a myarr
# we now have an empty array called myarr

2. to assign a value to an array element (one of the members of the array:
Code:
myarr[13]=4

This now means that the fourteenth (remember we chose to start counting from 0?)
contains 4.

3. So we want to enter ten numbers right? We need a loop to count from 0 .. 9
Code:
for i in 1 2 3 4 5 6 7 8 9
do
  # put your code here
done

i becomes 0 then 1,2,3..... as the loop goes on.

Code:
for i in 0 1 2 3 4 5 6 7 8 9
do
    echo -n 'Enter a number: '
    read myarr[$i]   # read lets you type in a number then assign it to a variable
done

You now have 10 array element, each of which has a number in it. Let's find the biggest one.
Code:
echo ${myarr[4]}  # NOTE the ${} part -when you want to get the value in an array element

So let us stomp thru the array and assign something to another variable, call it max
Code:
max=-2147483647  # I picked a negative number because your prof will do that to test 
# your code
# poor profs love to to go beyond what they tell you.... they think it somehow teaches (IMO)  

for i in 0 1 2 3 4 5 6 7 8 9
do
   [  $max -lt ${myarr[i] ] && max=${myarr[i]}
done

display the result:
Code:
echo "maximum value is $max"

Have fun....

PS:
Code:
[ $max -lt ${myarr[i] ] && max=${myarr}

is shell shorthand for if [ ] then do something endif.
 

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LEARN ABOUT CENTOS

dla_gerpvgrw.f

dla_gerpvgrw.f(3)						      LAPACK							 dla_gerpvgrw.f(3)

NAME

       dla_gerpvgrw.f -

SYNOPSIS

   Functions/Subroutines
       DOUBLE PRECISION function dla_gerpvgrw (N, NCOLS, A, LDA, AF, LDAF)
	   DLA_GERPVGRW

Function/Subroutine Documentation
   DOUBLE PRECISION function dla_gerpvgrw (integerN, integerNCOLS, double precision, dimension( lda, * )A, integerLDA, double precision,
       dimension( ldaf, * )AF, integerLDAF)
       DLA_GERPVGRW

       Purpose:

	    DLA_GERPVGRW computes the reciprocal pivot growth factor
	    norm(A)/norm(U). The "max absolute element" norm is used. If this is
	    much less than 1, the stability of the LU factorization of the
	    (equilibrated) matrix A could be poor. This also means that the
	    solution X, estimated condition numbers, and error bounds could be
	    unreliable.

       Parameters:
	   N

		     N is INTEGER
		The number of linear equations, i.e., the order of the
		matrix A.  N >= 0.

	   NCOLS

		     NCOLS is INTEGER
		The number of columns of the matrix A. NCOLS >= 0.

	   A

		     A is DOUBLE PRECISION array, dimension (LDA,N)
		On entry, the N-by-N matrix A.

	   LDA

		     LDA is INTEGER
		The leading dimension of the array A.  LDA >= max(1,N).

	   AF

		     AF is DOUBLE PRECISION array, dimension (LDAF,N)
		The factors L and U from the factorization
		A = P*L*U as computed by DGETRF.

	   LDAF

		     LDAF is INTEGER
		The leading dimension of the array AF.	LDAF >= max(1,N).

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 100 of file dla_gerpvgrw.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						 dla_gerpvgrw.f(3)
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