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(
AY) Details concerning the DESL
fit command.
(See
example(s)
of the use of the
fit
command.)
[Jump to the list of available options.]
General description of the
fit
command :
From existing files, the DESL "fit" command allows the user to create
new files containing values of specified dependent variables which
are the result of calculations using either an up-to-third order
piecewise-polyno or up-to-seventh order least-squares curve
fit with respect to an implied or specified set of independent
variable values.
Optionally, the newly calculated dependent variables can be first,
second, or third order analytical derivatives of the specified
dependent variables with respect to the specified independent
variable.
The list of currently available options
for the fit command is the following. Any names enclosed in
brackets are required
or are in a set of options,
one of which must be specified.
Any non-blinking names enclosed in
brackets are optional
or are in a set of options,
only one of which can be specified.
In cases where the option name is one of a set each different set number is indicated by
a red numeric set number
superscript trailing the respectiveright bracket :
[altvars]
[backward]
[coeffnames]
[cset]
[curve]
[degree]
[elsek]
[endifk]
[eqtol]
[]
[fitmethod]
[group]
[ifk]
[]
[newfiles]
[newfilex]
[nobias]
[noextrap]
[nofit]
[noop]
[noreordr]
[order]
[pathfile]
[paths]
[prefix]
[tol]
[values]
[vfiles]
[Top][Bottom][Option list]
( AYaltvars)
(Command :fit) Details for the altvars option.
[General syntax rules for this keyword.]
The presence of this option indicates that IF there
is an active composite alternate SIF variable name file
(as established via the "variables" DESL command) then
this composite file will be used to attempt to assign an
alternate SIF variable name if a SIF variable would
otherwise not be found on the file(s) being processed.
[Top][Bottom][Option list]
( AYbackward)
(Command :fit) Details for the backward option.
[General syntax rules for this keyword.]
Indicates that any searching for SIF variables will be
done from back to front in the SIF records. The default
condition is to search from front to back. This option
has no effect if "names" is not also given.
[Top][Bottom][Option list]
( AYcoeffnames)
(Command :fit) Details for the coeffnames option.
[General syntax rules for this keyword.]
Indicates the base strings to be used to generate dependent
variable coefficient names per file if the type fit
is "lsq" AND the option "nobias" has NOT been specified.
There should be one base string per dependent variable
and that base string should end in at least one numeral.
The base strings specified correspond to the FIRST in an
implied sequence of strings to be used as the names of
SIF variables containing the coefficients. As is the case
for any SIF variable name, the name string itself, expressed
or implied, can be no longer than 8 characters. The
sequence of name strings is built by incrementing the
base string's numeric suffic by one for each name generated.
The number of generated names depends on the order of the
lsq type fit which was performed. The default situation
is to NOT save the coefficients. Up to 199 base strings
can be specified.
Example : coeffnames CCL0 CCM0
[Top][Bottom][Option list]
( AYcset)
(Command :fit) Details for the cset option.
[General syntax rules for this keyword.]
This option is used to specify "file-specific" conditions
which, IN ADDITION to any other GLOBAL conditions which
ALSO may have been specified, are to be applied to each
SIF record processed from the respective SIF file. Just
like global conditions, file-specific conditions act to
limit the applicability of the DESL function being executed
by requiring that ALL applicable "and" conditions be TRUE
simultaneously or that at least ONE "or" condition be
TRUE.
The item immediately following "cset" is
the file sequence number in the "files" list for which the
following up-to-20 conditions will be applicable.
Each file-specific 3-item condition, like its global
3-item condition counterpart, is made up of (1) a SIF
variable name, (2) a 2-character logical conjunction,
and (3) a second SIF variable name or a constant.
Example : cset 3 alpha gt phi mach lt 1.2
Here, the user has indicated that, along with whatever
other GLOBAL conditions may have been specified, the
pertinent DESL function, for the THIRD file specified
or implied by the "files" list, will have its application
ALSO limited to records which satisfy BOTH of the two
conditions :
"ALPHA gt PHI" "MACH lt 1.2".
All file-specific conditions are implicitly joined by
an "and" conjunction; ie, by default, all file-specific
conditions would have to be true SIMULTANEOUSLY for
the applicable record to be retained.
If one or more file-specific conditions following
the file sequence number is to be connected to other
file-specific conditions for the same file number by
an "or" conjunction, then the 2-character item "or"
must immediately follow the file number.
Example : cset 2 or alpha lt 0 alpha gt 4
Here, the user has indicated that, along with whatever
other GLOBAL conditions may have been specified, the
pertinent DESL function, for the SECOND file specified
or implied by the "files" list, will have its application
ALSO limited to records in which the value of the SIF
variable "alpha" satisfies at least ONE of the conditions :
"ALPHA lt 0" "ALPHA gt 4".
Additionally, if the file number following the "cset"
option is negative, the absolute value of this negative
file number is used for the actual file number and the
associated "and" or "or" condition(s) are NOT used in the
traditional sense of filtering the records read but
are ONLY used to indicate when READING of the associated
file is to STOP. This ability is useful in preventing
the reading of a long file when it is known that the
data required is relatively near the beginning of the
file.
Example : cset -1 or run eq 3 alpha gt 24
Here, the user has indicated that when a record is
encountered for which either or both of the two conditions
"RUN = 3" "ALPHA gt 24"
is/are TRUE, reading of the current SIF file should end.
[Top][Bottom][Option list]
( AYcurve)
(Command :fit) Details for the curve option.
[General syntax rules for this keyword.]
Indicates the type of curve fit desired. Choices are
either "poly", indicating a piecewise-polyno fit,
or "lsq", indicating a least-squares fit. The default
curve type is "poly".
Example : curve lsq
[Top][Bottom][Option list]
( AYdegree)
(Command :fit) Details for the degree option.
[General syntax rules for this keyword.]
Indicates the degree of the fit to be calculated. The
default order is 0; ie, only a fit - no derivative.
Possible other choices are 1, 2 and 3, for first, second
and third order derivatives of the dependent variable(s)
with respect to the independent variable, respectively.
Example : degree 2
[Top][Bottom][Option list]
( AYeqtol)
(Command :fit) Details for the eqtol option.
[General syntax rules for this keyword.]
Indicates the tolerance to be applied to any global or
file-specific "eq" condition(s) which may have been
specified. If the tolerance value specified is positive
the value is in the units of the variable being used
in the respective condition(s). If the tolerance value
is negative the absolute value of the value is a
PERCENT difference. The default value of tolerance
is 0.
Example : eqtol .5
[Top][Bottom][Option list]
( AYfiles)
(Command :fit) Details for the files option.
[General syntax rules for this keyword.]
Indicates the list of existing SIF files to fit according
to the other options/argument specified.
If the "values" and/or "vfiles"
options are NOT specified, then the FIRST existing
file in each "group" of files in this list will determine
the set of independent variable values to use for the
fit calculations for the rest of the files in the group.
The set of independent variable values thus determined is
NOT subject to limitation(s) based on any conditions which
may have been specified.
This list of files can be implicitly extended via
use of the <list argument which can appear among
the specified file names. If one or more of the
<list-type arguments are specified, where "list" is
a currently defined file name list, the file names
contained in the indicated file name list(s) will be
included, at their respective point(s) of encounter,
in the current file list. The referenced list(s)
must have been produced by the "newfiles" and/or
"newfilex" argument lists associated with one or more
previously executed DESL commands. Each "list" name
can be up to 15 characters long.
File names can also include the {...} construct. This
type specification within a file name implies that the
list name given between the
curly brackets ( {} ), is to be used to have each of
its elements substituted in turn for the { ... },
inclusively, such that an implicit lengthening of
the file list is accomplished, up to the maximum
number of files allowed. Any time such a {...}
usage occurs, all lists mentioned must exist;
i.e., must have been previously defined in the current
DESL session. Only one {...} construct
can be included in a file name. Including more than
one such construct will result in unpredictable results.
An example of this type of file name specification is
the following :
t43r{runs}.sif
Here, the list "runs" will have its elements used, in
turn, in place of the {runs} substring.
| . |
(Begin modifications on 052102)
Each file name, whether it includes the {...} or not,
can be a maximum of 256 characters long.
If a file name is more than 16 characters long it
must be enclosed in question marks (?) .
(End modifications on 052102) |
Up to 200 files can be explicitly or implicitly specified.
Example : files batch1 batch7 <flist2 <flist5
[Top][Bottom][Option list]
( AYfitmethod)
(Command :fit) Details for the fitmethod option.
[General syntax rules for this keyword.]
The value following this option indicates which previous
polynomial fitting method to use. The default method is
the latest method. Method 1 was employed from the
inception of DESL until approximately 1/25/99. This
method involved, for the determination of the coefficients
of a second or third order fit, the solution of two
second or third order equations, respectively, and one
or two lower order equations which governed the slopes
of the piecewise line through the points in question.
The latest method involves the solution of three or four
second or third order equations without any governance
of the slopes.
Example : fitmethod 1
[Top][Bottom][Option list]
( AYgroup)
(Command :fit) Details for the group option.
[General syntax rules for this keyword.]
If "group" is specified and "values" is not specified
the total number of files to be fit, as specified by the
"files" option/argument list, will be divided into
"groups", each one having a constant number of
files. Then, instead of the set of "values" to be used
in the fit being extracted from only the first file in the
"files" list, they will be extracted from the first file
in each "group" of files in the "files" list. Each set
of these values will be applicable only to other files
in the same group. The number of files in a "group"
should be evenly divisible into the total number of files
specified via "files".
Example : group 3
[Top][Bottom][Option list]
( AYnames)
(Command :fit) Details for the names option.
[General syntax rules for this keyword.]
Indicates, in this required order, (1) the name of the
independent variable, and (2) the names of the dependent
variables to be accessed from each of the specified files
in the "files" list to calculate the new "curve-fit"
files. At least one dependent variable must be specified.
Up to 200 names can be specified. (One independent
variable name and 199 dependent variable names.)
If the special name "all" is specified after the name of
the independent variable the implication is that the
user wishes as many SIF variables as possible, up to the
200-name limit and NOT including the name of the independent
variable or any "nofit" names which could have also been
specified, to be included in the implied list of dependent
variables. The "names" expansion via the use of "all"
is done ONCE per GROUP of files being fit; the list
of dependent variable names built via "all" is built
from the names in the beginning of the FIRST file in
each group of files being processed.
Example : names alpha cp101 thru cp120
[Top][Bottom][Option list]
( AYnewfiles)
(Command :fit) Details for the newfiles option.
[General syntax rules for this keyword.]
Indicates the desired names for new files being produced.
There is an understood 1:1 correspondence between files
in the "files" list and files in the "newfiles" list.
A new file name prefixed with the 4-character string
"null" can be used as a place holder in the "newfiles"
file names list. This type of name is converted to a
blank string before it is used; ie, using a "null"
prefixed name is equivalent to having not specified
that name at all. By default, all files explicitly
named via this "newfiles" list will be flagged as a
file "to be RETAINED" at cleanup. (See the "cleanup"
command.) The default file name generated for a new
file not explicitly named via "newfiles" or "newfilex"
is the 3-character string "gen" followed by a unique
numeric suffix. Up to 200 new files can be specified.
The list of the names of the new files actually produced
can be saved via the use of the ">list"- or ">>list"-
type argument, which can appear among the specified
new file names. If a ">list"- or ">>list"-type argument
is specified, where "list" is the specified file name
list, the names of the new files which DESL actually
produces during the execution of the current command
will be saved in the specified file name list.
This file name list can later be referenced by the
"files"/"xfiles" options to imply the file names
contained therein. Up to 200 new file names can be
saved in any one list. If the ">list" argument is
specified the named list will be created if it does not
already exist, or will overwrite a like-named list if
one exists. If the ">>list" argument is specified the
named list will be appended to if it exists or will be
created if it does not exist. All file name lists
are in existence for the current DESL session only.
Each "list" name can be up to 15 characters long.
In all but a few noted cases, it is acceptable to use
the ">list" or ">>list"-type argument without specifying
a full complement of actual new file names. Any new
file produced whose NAME is GENERATED by DESL is ALWAYS
marked as a file to "PURGE at cleanup".
A suffix which may be in effect as established via
the filesuffix DESL
command will be added to any expressed or implied
new file name.
New file names can also include the {...} construct.
This type specification within a file name implies
that the list name given
between the curly brackets ( {} ), is to be used to
have each of its elements substituted in turn for
the { ... }, inclusively, such that an implicit
lengthening of the new file list is accomplished,
up to the maximum number of new files allowed. Any
time such a {...} usage occurs, all lists mentioned
must exist; i.e., must have been previously
defined in the current DESL session. Only
one {...} construct can be included in a
new file name. Including more than one such construct
will result in unpredictable results.
An example of this type of new file name specification
is the following :
t43r{runs}.sif
Here, the list "runs" will have its elements used, in
turn, in place of the {runs} substring.
| . |
(Begin modifications on 052102)
Each new file name, whether it includes the {...} or
not can be a maximum of 256 characters long.
If a newfile name is more than 16 characters long
it must be enclosed in question marks (?).
(End modifications on 052102) |
Example : newfiles new1 thru new9 >flist9
[Top][Bottom][Option list]
( AYnewfilex)
(Command :fit) Details for the newfilex option.
[General syntax rules for this keyword.]
This option has exactly the same function as the
option "newfiles" except that all new files created
via a "newfilex" name are flagged as files to "PURGE
at cleanup". (See "newfiles" option. See
"cleanup" command.) Up to 200 new files can be
specified.
Example : newfilex new1 thru new9
[Top][Bottom][Option list]
( AYnoextrap)
(Command :fit) Details for the noextrap option.
[General syntax rules for this keyword.]
Indicates that, if to satisfy the fit to the expressed
or implied set of independent variable values,
extrapolation must be performed, then it is not allowed.
By default, extrapolation is allowed. It should be pointed
out that if extrapolation is done, it is always linear.
[Top][Bottom][Option list]
( AYnobias)
(Command :fit) Details for the nobias option.
[General syntax rules for this keyword.]
Normally, to try to account for circumstances in which
the magnitude of the implied or expressed independent
variable values is large, the independent variable
values are "biased" by their mean value before the
arithmetic is done to compute the fitted curves'
coefficients. The accuracy of the resulting fitted
values of dependent variable(s) is improved by biasing.
If it is desired that no biasing be done in the process
of determining the new values of dependent variable(s)
the "nobias" option can be specified.
[Top][Bottom][Option list]
( AYnofit)
(Command :fit) Details for the nofit option.
[General syntax rules for this keyword.]
Indicates the SIF variables to carry, but not fit, from
each of the files being fit into the new files being
created. The values these variables will have in the
new file(s) will be the average value they had in all
applicable records of the respective file(s) being fit.
Normally, ONLY those variables which have values which
remain constant or effectively constant throughout a
file should be included in a "nofit" list. Up to 200
"nofit" names can be specified.
Example : nofit test run
[Top][Bottom][Option list]
( AYnoop)
(Command :fit) Details for the noop option.
[General syntax rules for this keyword.]
A dummy option which allows one or more GLOBAL conditions
to follow. This option has NO OTHER FUNCTION.
[Top][Bottom][Option list]
( AYnoreordr)
(Command :fit) Details for the noreordr option.
[General syntax rules for this keyword.]
Normally both the specified or implied set of desired
independent variable values and the set of independent
variable values corresponding to the data being fit
will be reordered such that their values are monotonically
increasing in magnitude throughout the sets. If
it is desired that this type reordering should not occur
then the "noreordr" option should be specified.
[Top][Bottom][Option list]
( AYorder)
(Command :fit) Details for the order option.
[General syntax rules for this keyword.]
Indicates the highest order of curve fit allowed.
The maximum order of fit when "curve" = "poly" is 3.
The maximum order of fit when "curve" = "lsq" is 7.
In some cases, when the situation regarding the number of
existing data points in a file dictates it, the specified
order may be temporarily reduced. The default order is
one (linear). During polynomial ("curve" = "poly")
extrapolation, the order is always one.
Example : order 3
[Top][Bottom][Option list]
( AYpathfile)
(Command :fit) Details for the pathfile option.
[General syntax rules for this keyword.]
If specified, any up-to-16-charact string specified
via the "paths" option and argument list can be
translated to an up-to-64-charact string. If
a specified "paths" string matches a string in the
left column in the path file, then the (potentially
longer) string in the right column in the same line
in the path file is substituted for the original
string. The rules
for the syntax of a path file are the following :
- all lines are ASCII
- any line beginning with "* " is a comment and
is ignored (asterisk + one or more blanks)
- blank lines are ignored
- only 2 items per line per translation : the first
up to 16 characters and the second up to 64
characters. Any string longer than 16 characters MUST
be enclosed in question-mark (?) delimiters.
- free-field interpretation, therefore
embedded blanks require the "?" delimiters
- first item is name to be translated; must
match VERBATIM with path name specified or implied
via "paths" argument list
- second item is the corresponding path name translation
An example of such a file is the following :
*
* Example path file for test xxx
*
* item 1 = path to be translated : MUST
* match VERBATIM with name given
* specified/implied via "paths"
*
* item 2 = resulting name translation
*
data56 ? \usr\home2\ people\test56\ ?
up ?..\?
way-up ? ..\..\..\ Temp46\?
Example : pathfile pathA
[Top][Bottom][Option list]
( AYpaths)
(Command :fit) Details for the paths option.
[General syntax rules for this keyword.]
Indicates, in a 1:1 correspondence with the list of
files specified, directory locations for the specified
files. These locations supersede the current directory.
If a file location thus specified is not empty ("null...")
a search for the respective file will be made at the
indicated location before a search is made
at any other alternate locations which have been made
effective via a previous execution of the "path" command.
By default, all path names are blank. Up to 200 path
names can be specified.
Example : paths ..\ ..\Main\ sub1\
[Top][Bottom][Option list]
( AYprefix)
(Command :fit) Details for the prefix option.
[General syntax rules for this keyword.]
Indicates the string to be prefixed to each calculated
dependent variable name in the file(s) being created. By
default, no prefix is added to such names.
Example : prefix FT
[Top][Bottom][Option list]
( AYtol)
(Command :fit) Details for the tol option.
[General syntax rules for this keyword.]
Sets the allowable tolerance between adjacent independent
variable values in each set of such variable values being
being used for the curve fit. Successive values of the
independent variable are not used to determine the curve
fit if they fall within the specified tolerance of the
most previous retained independent variable value.
If the specified tolerance value is negative, it is
assumed to be a tolerance in percent, and the tolerance
percent value is the absolute magnitude of the number
specified. The default tolerance is 1 percent.
Normally, the "set" of independent variable values are
reordered to be monotonically increasing after they are
collected. The tolerance value is, therefore, applied
normally to this strictly-increas set of values. If the
set of values has been prevented from being sorted so its
values are increasing, via the "noreordr" option, the
"tol" value would be applied to this non-reordered set.
Example : tol -.3
[Top][Bottom][Option list]
( AYvalues)
(Command :fit) Details for the values option.
[General syntax rules for this keyword.]
Indicates the set of independent variable values to use
for each file being fit. The default set of independent
variable values is that which is extracted from the first
existing file of each "group" of files in the "files" list
or the respective file named in the "vfiles" argument list
per group of files. If both "values" AND "vfiles" are
specified, "values" has precedence. Up to 2500 values
can be specified.
The actual limit of the number of values which can be
specified via "values" or implied by the omission of
of "values" but use of "vfiles" is 5000/(1+ndep), where
"ndep" is the number of dependent variables specified.
The independent variable values entered via "values" are
NOT subject to limitation(s) based on any conditions which
may have been specified.
Example : values 3.7 4.2 6.7 10 to 20 by 1
[Top][Bottom][Option list]
( AYvfiles)
(Command :fit) Details for the vfiles option.
[General syntax rules for this keyword.]
Indicates, per "group" of files, the file(s) to access to
attempt to extract values of the independent variable for
each file being fit.
The actual limit of the number of values which can be
established via the use of "vfiles" is 5000/(1+ndep),
where, "ndep" is the number of dependent variables
specified.
| . |
(Begin modifications on 081202)
If one or more global and/or file-specific conditions are
specified they will NOT be used during this process of
determining the independent variable values.
(End modifications on 081202) |
[Top][Bottom][Option list]
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