Whats New in Release 2

Critical Changes in Behaviour

Generally we seek to maintain upward compatability so that ASReml 1.00 code will continue to run. However, to deliver improved facilities, some changes to behaviour are unavoidable.


ASReml will automatically increase workspace in large jobs if it needs it and it is available. The default workspace is 32Mbyte but the user can specify a larger amount (see Section 3.2). In any case, if a job runs out of workspace when it is running, and has not already claimed the maximum amount of workspace permitted on the computer, ASReml will restart the job with a larger allocation.

Storage of alphabetic factor labels

In release 1.00, there was a fixed allocation for alphabetic labels of 5000 labels of up to 20 characters each. Longer labels were truncated and regarded as equivalent if identical in the first 20 characters.

In release 2.00, the allocation is dynamic with default provision for 2000 labels of 16 characters each (see Section 5.1). However, the allocation is increased to make provision for the declared size of all alphabetic factors and the label length can be set using the !LL qualifier. If the number of levels is overspecified, the !PRUNE qualifier may be used to readjust the sizes.

Slash operator in the model specificaton

In model specification, A/B now expands to A A.B


In this version, graphics have been converted from Interacter to Winteracter except that MENU mode has been removed, being replaced by WinASReml. This should not alter the appearance of any of the graphs produced.

Singularities in Average Information matrix

Singularities in ASReml arise in three contexts: the linear model, the variance model and the Average Information (AI) matrix. The AI matrix is used to give updates to the variance parameter estimates. The AI matrix is used to give updates to the variance parameter estimates. In release 1.00, if singularities were present in the AI matrix, a generalised inverse was used which effectively conditioned on whichever parameters were identified as singular. ASReml now aborts processing if singularities appear unless the !AISINGULARITIES qualifier is set. Which particular parameter is singular is reported in the variance component table printed in the .asr file.

The most common reason for singularities is that the user has overspecified the model and is likely to misinterpret the results if not fully aware of the situation. Overspecification will occur in a direct product of two unconstrained variance matrices, when a random term is confounded with a fixed term and when there is no information in the data on a particular component. The best action is to reform the variance model so that the ambiguity is removed, or to fix one of the parameters in the variance model so that the model can be fitted. Only rarely will it be reasonable to specifiy the !AISINGULARITIES qualifier.


The order predicted values are presented has changed and are now under user control: the factors are presented in the order they are declared on the PREDICT statement. The predicted values are ordered so that the rightmost factor rotates fastest, followed by the second from the right.

Extended Factor Analytic

XFA model fitting with some specific variances zero is extended to allow direct product structures of XFA with other structures (previously only XFA with Identity was allowed) provided the other structure is not another XFA with some zero specific variances, and to allow several model terms to have XFA structures involving zero specific variances. The work around for XFA x XFA (both with zero PSIs) is to fix 'ZERO' PSIs in one of the terms at 0.0001. In 3-way terms involving an XFA with zero specific variance, the central component must be an Identity. I.e. XFA x I x C and C x I x XFA are allowed where C is some structure and I the Identity.

ASReml update changes

Changes to the rules for when the AI update of a variance parameter is replaced by a smaller update have been made to make the process more robust. Consequently, the iteration sequence may differ slightly in some jobs from earlier versions. It should end up at effectively the same point with only small numerical differences in the results. These rules come into play when the simple AI update is large (10 fold) or would put the parameter 'out of bounds'.

BLUEs in .asr file

In release 1.00, the non-zero BLUEs (estimates of fixed effects) were reported in the .asr file as well as in the .sln file. In release 2.00, the BLUEs are not reported in the .asr file unless the !BRIEF -1 qualifier is set or there are less than 10 BLUEs to report.

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