readme.aireml
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- | AIREMLF90 | + | ====== |
- | A modification of REMLF90 with computing by the Average-Information | + | ===== Summary ===== |
- | Algorithm. | + | A modification of REMLF90 |
- | + | \\ | |
- | Initially written by Shogo Tsuruta, University of Georgia, | + | \\ |
- | + | See PREGSF90 with genotypes | |
- | + | ||
- | AIREMLF90 uses a second derivative REML algrithm | + | |
- | described in Jensen et al. (1996-7). For most problems, it converges in far | + | |
- | fewer rounds than EM REML as implemented in REMLF90. While typically REMLF90 | + | |
- | takes 50-300 rounds to converge, AIREMLF90 converges in 5-15 rounds and to a | + | |
- | higher accuracy. | + | |
- | covariance matrix is close to non-positive definite. Adjust sensitivity of the | + | |
- | program by setting the appropriate tolerance. | + | |
- | + | ||
- | + | ||
- | Several options are avaiable: | + | |
- | + | ||
- | + | ||
- | OPTION conv_crit 1d-12 | + | |
- | + | ||
- | convergence criterion | + | |
- | + | ||
- | OPTION maxrounds 500 | + | |
- | + | ||
- | maximum rounds (default 5000). | + | |
- | when it is negative, the program calculates BLUP without running REML. | + | |
- | + | ||
- | OPTION EM-REML 10 | + | |
- | + | ||
- | run EM-REML (REMLF90) for first 10 rounds to get initial variances within the | + | |
- | parameter space (default 0). | + | |
+ | ===== Options ===== | ||
+ | < | ||
+ | OPTION conv_crit 1d-10 | ||
+ | </ | ||
+ | Convergence criterion (default 1d-12). | ||
+ | < | ||
+ | OPTION maxrounds n | ||
+ | </ | ||
+ | Maximum rounds (default 5000). When n = 0, the program calculates BLUP without iterating REML and provides some statistics (-2logL, AIC, SE for (co)variances, | ||
+ | < | ||
+ | OPTION EM-REML n | ||
+ | </ | ||
+ | Run EM-REML (REMLF90) for first n rounds to get initial starting variances for AIREMLF90 within the parameter space (default 0). With n is large (e.g., 1000, 10000, ....), AIREMLF90 runs as REMLF90 until convergence, | ||
+ | < | ||
+ | OPTION use_yams | ||
+ | </ | ||
+ | Run the program with YAMS (modified FSPAK). The computing time can be dramatically improved. | ||
+ | < | ||
OPTION tol 1d-12 | OPTION tol 1d-12 | ||
- | + | </ | |
- | | + | Tolerance |
- | | + | Convergence may be much faster by changing this value. |
- | | + | < |
OPTION sol se | OPTION sol se | ||
+ | </ | ||
+ | Store solutions and those standard errors. | ||
+ | < | ||
+ | OPTION store_pev_pec 6 | ||
+ | </ | ||
+ | Store triangular matrices of standard errors and its covariances for correlated random effects such as direct-maternal effects and random-regression effects in " | ||
+ | < | ||
+ | OPTION residual | ||
+ | </ | ||
+ | y-hat and residuals will be included in " | ||
+ | < | ||
+ | OPTION missing -999 | ||
+ | </ | ||
+ | Specify the missing value (default 0) in integer. | ||
+ | < | ||
+ | OPTION constant_var 5 1 2 ... | ||
+ | </ | ||
+ | 5: effect number\\ | ||
+ | 1: first trait number\\ | ||
+ | 2: second trait number\\ | ||
+ | implying the covariance between traits 1 and 2 for effect 5. | ||
- | store solutions and s.e. | + | **Heterogeneous residual variances for a single trait** |
+ | < | ||
+ | OPTION hetres_pos 10 11 | ||
+ | </ | ||
+ | Specify the column positions of (two) covariables in the data file. | ||
+ | < | ||
+ | OPTION hetres_pol 4.0 0.1 0.1 | ||
+ | </ | ||
+ | Initial values of coefficients for heterogeneous residual variances using //ln//(a0, a1, a2, ...) to make these values. | ||
- | OPTION | + | **Heterogeneous residual variances for multiple traits**\\ |
+ | Convergence will be very slow with multiple trait heterogeneous residual variances | ||
+ | < | ||
+ | OPTION | ||
+ | </ | ||
+ | or | ||
+ | < | ||
+ | OPTION hetres_pos 10 11 12 13 | ||
+ | </ | ||
+ | Specify the column positions of covariables (trait first) in the data file. | ||
+ | "10 10" or "10 11" could be linear for first and second traits.\\ | ||
+ | "11 11" or "12 13" could be quadratic. | ||
+ | < | ||
+ | OPTION hetres_pol 4.0 4.0 0.1 0.1 0.01 0.01 | ||
+ | </ | ||
+ | Initial values of coefficients for heterogeneous residual variances using //ln//(a0, a1, a2, ...) to make these values (trait first).\\ | ||
+ | "4.0 4.0" are intercept for first and second traits.\\ | ||
+ | "0.1 0.1" could be linear and "0.01 0.01" could be quadratic.\\ | ||
+ | To transform back to the original scale, use exp(a0+a1*X1+a2*X2). | ||
+ | < | ||
+ | OPTION SNP_file snp | ||
+ | </ | ||
+ | Specify the SNP file name to use genotype data. | ||
- | set the missing value (default 0). | + | < |
+ | As an alternative of SE, calculate SD for function of (co)variances by repeated sampling of parameters estimates from their asymptotic multivariate normal distribution, | ||
+ | \\ | ||
+ | ''< | ||
+ | A name for a particular function (e.g., '' | ||
+ | \\ | ||
+ | ''< | ||
+ | A formula to calculate a function of (co)variances to estimate SD. All terms of the function should be written with no spaces.\\ | ||
+ | \\ | ||
+ | Each term of the function corresponds to (co)variance elements and could include any random effects (G) and residual (R) (co)variances.\\ | ||
+ | \\ | ||
+ | Notation is with reference to the effect number and the trait number ('' | ||
+ | where '' | ||
+ | '' | ||
+ | \\ | ||
+ | Several functions could be added, with one OPTION line per function.\\ | ||
+ | \\ | ||
+ | Examples: | ||
+ | \\ | ||
+ | '' | ||
+ | '' | ||
- | # Heterogeneous residual variances for a single trait | + | '' |
- | OPTION | + | '' |
+ | \\ | ||
+ | The first function calculates the SD for the total variance for a maternal model with permanent maternal effect, where 2 and 3 are the effect number for the direct and maternal additive genetic effects respectively, | ||
+ | |||
+ | The second function calculates the heritability for the direct component. | ||
- | specify | + | The third function |
- | OPTION hetres_pol 4.0 0.1 0.1 | + | The fourth function calculates the SD of the genetic correlation between traits |
- | initial values | + | < |
- | use ln(a0, a1, a2, ...) to make these values. | + | Set the number |
+ | default value 10000 | ||
+ | < | ||
+ | Indicate to store in file samples of (co)variances function for postprocessing | ||
+ | ===== Tricks ===== | ||
+ | When the covariance matrix is close to non-positive definite, the AIREMLF90 may not converge. | ||
+ | There are two options you might want to try: | ||
- | # Heterogeneous residual variances for mutiple traits | + | 1. change the tolerance value (xx) in the option: |
- | OPTION | + | OPTION |
- | specify the position of covariables | + | to a very strict value (e.g., 1d-20) or a lenient value (1d-06). |
- | OPTION hetres_pol 4.0 4.0 0.1 0.1 0.01 0.01 | + | 2. use an option to use EM-REML inside AI-REML: |
- | initial values of coefficients for heterogeneous residual variances | + | OPTION EM-REML xx |
- | use ln(a0, a1, a2, ...) to make these values (trait first). | + | |
+ | where xx is the number of iterations for EM-REML you expect to get a good starting value for AI-REML. After running xx rounds with EM-REML, the AIREMLF90 program will automatically switch from EM-REML to AI-REML using the last estimate from EM-REML as a starting value for AI-REML. | ||
readme.aireml.txt · Last modified: 2024/03/25 18:22 by 127.0.0.1