NAG C Library Function Document

nag_rand_2_way_table (g05pzc)

1

Purpose

2

Specification

3

Description

4

References

5

Arguments

1:    $\mathbf{mode}$ – Nag_ModeRNGInput

On entry: a code for selecting the operation to be performed by the function.

$\mathbf{mode}=\mathrm{Nag\_InitializeReference}$

Set up reference vector only.

$\mathbf{mode}=\mathrm{Nag\_GenerateFromReference}$

Generate two-way table using reference vector set up in a prior call to nag_rand_2_way_table (g05pzc).

$\mathbf{mode}=\mathrm{Nag\_InitializeAndGenerate}$

Set up reference vector and generate two-way table.

Constraint: $\mathbf{mode}=\mathrm{Nag\_InitializeReference}$, $\mathrm{Nag\_GenerateFromReference}$ or $\mathrm{Nag\_InitializeAndGenerate}$.

2:    $\mathbf{nrow}$ – IntegerInput

On entry: $m$, the number of rows in the table.

Constraint: $\mathbf{nrow}\ge 2$.

3:    $\mathbf{ncol}$ – IntegerInput

On entry: $n$, the number of columns in the table.

Constraint: $\mathbf{ncol}\ge 2$.

4:    $\mathbf{totr}\left[\mathbf{nrow}\right]$ – const IntegerInput

On entry: the $m$ row totals, $R_{\mathit{i}}$, for $\mathit{i}=1,2,\dots ,m$.

Constraints:

• $\mathbf{totr}\left[\mathit{i}-1\right]\ge 0$, for $\mathit{i}=1,2,\dots ,m$;
• ${\displaystyle \sum _{i=1}^m}\mathbf{totr}\left[i-1\right]={\displaystyle \sum _{j=1}^n}\mathbf{totc}\left[j-1\right]$;
• ${\sum }_{\mathit{i}}\mathbf{totr}\left[\mathit{i}-1\right]>0$, for $\mathit{i}=1,2,\dots ,m$.

5:    $\mathbf{totc}\left[\mathbf{ncol}\right]$ – const IntegerInput

On entry: the $n$ column totals, $C_{\mathit{j}}$, for $\mathit{j}=1,2,\dots ,n$.

Constraints:

• $\mathbf{totc}\left[\mathit{j}-1\right]\ge 0$, for $\mathit{j}=1,2,\dots ,n$;
• ${\displaystyle \sum _{j=1}^n}\mathbf{totc}\left[j-1\right]={\displaystyle \sum _{i=1}^m}\mathbf{totr}\left[i-1\right]$.

6:    $\mathbf{r}\left[\mathbf{lr}\right]$ – doubleCommunication Array

On entry: if $\mathbf{mode}=\mathrm{Nag\_GenerateFromReference}$, the reference vector from the previous call to nag_rand_2_way_table (g05pzc).

On exit: the reference vector.

7:    $\mathbf{lr}$ – IntegerInput

On entry: the dimension of the array r.

Constraint: $\mathbf{lr}\ge {\displaystyle \sum _{i=1}^{\mathbf{nrow}}}\mathbf{totr}\left[i-1\right]+5$.

8:    $\mathbf{state}\left[\mathit{dim}\right]$ – IntegerCommunication Array

Note: the dimension, $\mathit{dim}$, of this array is dictated by the requirements of associated functions that must have been previously called. This array MUST be the same array passed as argument state in the previous call to nag_rand_init_repeatable (g05kfc) or nag_rand_init_nonrepeatable (g05kgc).

On entry: contains information on the selected base generator and its current state.

On exit: contains updated information on the state of the generator.

9:    $\mathbf{x}\left[\mathbf{nrow}\times \mathbf{pdx}\right]$ – IntegerOutput

On exit: if $\mathbf{mode}=\mathrm{Nag\_GenerateFromReference}$ or $\mathrm{Nag\_InitializeAndGenerate}$, a pseudorandom two-way $m$ by $n$ table, $X$, with element $\mathbf{x}\left[\left(i-1\right)\times \mathbf{pdx}+j-1\right]$ containing the $\left(i,j\right)$th entry in the table such that ${\displaystyle \sum _{\mathit{i}=1}^m}\mathbf{x}\left[\left(i-1\right)\times \mathbf{pdx}+j-1\right]=\mathbf{totc}\left[j-1\right]$ and ${\displaystyle \sum _{\mathit{j}=1}^n}\mathbf{x}\left[\left(i-1\right)\times \mathbf{pdx}+j-1\right]=\mathbf{totr}\left[i-1\right]$

10:  $\mathbf{pdx}$ – IntegerInput

On entry: the stride separating matrix column elements in the array x.

Constraint: $\mathbf{pdx}\ge \mathbf{ncol}$.

11:  $\mathbf{fail}$ – NagError *Input/Output

The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).

6

Error Indicators and Warnings

NE_ALLOC_FAIL

Dynamic memory allocation failed.
See Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.

NE_BAD_PARAM

On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.

NE_INT

On entry, lr is not large enough, $\mathbf{lr}=〈\mathit{\text{value}}〉$: minimum length required $=〈\mathit{\text{value}}〉$.

On entry, $\mathbf{ncol}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{ncol}\ge 2$.

On entry, $\mathbf{nrow}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{nrow}\ge 2$.

NE_INT_2

On entry, $\mathbf{pdx}=〈\mathit{\text{value}}〉$ and $\mathbf{ncol}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{pdx}\ge \mathbf{ncol}$.

On entry, $\mathbf{pdx}=〈\mathit{\text{value}}〉$ and $\mathbf{nrow}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{pdx}\ge \mathbf{nrow}$.

NE_INT_ARRAY

On entry, at least one element of totr is negative or totr sums to zero.

On entry, totc has at least one negative element.

NE_INT_ARRAY_2

On entry, the arrays totr and totc do not sum to the same total: totr array total is $〈\mathit{\text{value}}〉$, totc array total is $〈\mathit{\text{value}}〉$.

NE_INTERNAL_ERROR

An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 2.7.6 in How to Use the NAG Library and its Documentation for further information.

NE_INVALID_STATE

On entry, state vector has been corrupted or not initialized.

NE_NO_LICENCE

Your licence key may have expired or may not have been installed correctly.
See Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.

NE_PREV_CALL

nrow or ncol is not the same as when r was set up in a previous call.
Previous value of $\mathbf{nrow}=〈\mathit{\text{value}}〉$ and $\mathbf{nrow}=〈\mathit{\text{value}}〉$.
Previous value of $\mathbf{ncol}=〈\mathit{\text{value}}〉$ and $\mathbf{ncol}=〈\mathit{\text{value}}〉$.

7

Accuracy

8

Parallelism and Performance

9

Further Comments

10

Example

10.1

Program Text

Program Text (g05pzce.c)

10.2

Program Data

10.3

Program Results

Program Results (g05pzce.r)