EViews Help: Coef

Object Reference : Object View and Procedure Reference : Coef

Coef

Coefficient vector. Coefficients are used to represent the parameters of equations and systems.

Coef Declaration

coef declare coefficient vector.

There are two ways to create a coef. First, enter the coef keyword, followed by a name to be given to the coefficient vector. The dimension of the coef may be provided in parentheses after the keyword:

coef alpha

coef(10) beta

If no dimension is provided, the resulting coef will contain a single element.

You may also combine a declaration with an assignment statement. If you do not provide an explicit assignment statement, a new coef vector will be initialized to zero.

See also param for information on initializing coefficients, and the entries for each of the estimation objects ( Equation, Logl, Pool, Sspace, System, and Var) for additional methods of accessing coefficients.

Coef Views

display display table, graph, or spool in object window.

label label view.

sheet spreadsheet view of the coefficient.

stats descriptive statistics.

Coef Procs

clearcollabels clear the column label in a coef object.

clearhist clear the contents of the history attribute.

clearremarks clear the contents of the remarks attribute.

clearrowlabels clear the row labels in a coef object.

copy creates a copy of the coef.

displayname set display name.

export save as Excel 2007 XLSX, CSV, tab-delimited ASCII text, RTF, HTML, Enhanced Metafile, PDF, TEX, or MD file on disk.

fill fill the elements of the coefficient vector.

import imports data from a foreign file into the object.

olepush push updates to OLE linked objects in open applications.

read import data into coefficient vector.

resize resize the coef object.

setattr set the value of an object attribute.

setcollabels set the column label in a coef object.

setformat set the display format for the coefficient vector spreadsheet.

setindent set the indentation for the coefficient spreadsheet.

setjust set the horizontal justification for all cells in the spreadsheet view of the coef object.

setrowlabels set the row labels in a coef object.

setwidth set the column width for the coefficient spreadsheet.

showlabels displays the custom row and column labels of a coef spreadsheet.

write export data from coefficient vector.

Coef Graph Views

Graph creation views are discussed in detail in “Graph Creation Command Summary”.

area area graph.

bar bar graph.

boxplot boxplot graph.

distplot distribution graph.

dot dot plot graph.

line line graph.

qqplot quantile-quantile graph.

spike spike graph.

Coef Data Members

@attr("arg") string containing the value of the arg attribute, where the argument is specified as a quoted string.

@collabels string containing the column label of the coef.

@description string containing the Coef object’s description (if available).

@detailedtype string describing the object type: “COEF”.

@displayname string containing the Coef object’s display name. If the Coef has no display name set, the name is returned.

@droprow(arg) Returns the Coef with the rows defined by arg removed. arg may be an integer, vector of integers, string, or svector of strings. Integer values correspond to rows and string values correspond to previously defined row labels.

@name string containing the Coef object’s name.

@remarks string containing the Coef object’s remarks (if available).

@row(arg) Returns the rows defined by arg. arg may be an integer, vector of integers, string, or svector of strings. Integer values correspond to rows and string values correspond to previously defined row labels.

@rowlabels string containing the row labels of the coef.

@rows number of rows in the coef.

@type string describing the object type: “COEF”.

@updatetime string representation of the time and date at which the Coef was last updated.

(i) i-th element of the coefficient vector. Simply append “(i)” to the coef name (without a “.”).

Coef Examples

The coefficient vector declaration:

coef(10) coef1=3

creates a 10 element coefficient vector COEF1, and initializes all values to 3.

Suppose MAT1 is a

matrix, and VEC1 is a 20 element vector. Then:

coef mycoef1=coef1

coef mycoef2=mat1

coef mycoef3=vec1

create, size, and initialize the coefficient vectors MYCOEF1, MYCOEF2 and MYCOEF3.

Coefficient elements may be referred to by an explicit index. For example:

vector(10) mm=beta(10)

scalar shape=beta(7)

fills the vector MM with the value of the tenth element of BETA, and assigns the seventh value of BETA to the scalar SHAPE.

clearcollabels

Coef Procs

Clear the column label in a coef object.

Syntax

coef_name.clearcollabels

Examples

c1.clearcollabels

clears the custom column label from the coef C1.

Cross-references

See also Coef::write.

fill	Coef Procs

Fill a coef object with specified values.

Syntax

coef_name.fill(options) n1[, n2, n3 …]

Follow the keyword with a list of values to place in the specified object. Each value should be separated by a comma.

Running out of values before the coef vector is completely filled is not an error; the remaining cells or observations will not be modified unless the “l” option is specified. However, if you list more values than the coef vector can hold, EViews will not modify any observations and will return an error message.

Options

l	Loop repeatedly over the list of values as many times as it takes to fill the coef vector.
o=integer (default=1)	Fill the coef vector from the specified element. Default is the first element.

Examples

The following example declares a four element coefficient vector MC, initially filled with zeros. The second line fills MC with the specified values and the third line replaces from row 3 to the last row with –1.

coef(4) mc

mc.fill 0.1, 0.2, 0.5, 0.5

mc.fill(o=3,l) -1

Note that the last argument in the fill command above is the letter “l”.

Cross-references

See “Fill assignment” for further discussion of the fill procedure.

import

Coef Procs

Imports data from a foreign file into the coef object.

Syntax

coef_name.import([type=]) source_description import_specification

• source_description should contain a description of the file from which the data is to be imported. The specification of the description is usually just the path and file name of the file, however you can also specify more precise information. See wfopen for more details on the specification of source_description.

• The optional “type=” option may be used to specify a source type. For the most part, you should not need to specify a “type=” option as EViews will automatically determine the type from the filename. The following table summaries the various source formats and along with the corresponding “type=” keywords:

	Option Keywords
Excel (through 2003)	“excel”
Excel 2007 (xml)	“excelxml”
HTML	“html”
Text / ASCII	“text”

• import_specification can be used to provide additional information about the file to be read. The details of import_specification will depend upon the type of file being imported.

Excel Files

Excel Examples

The syntax for reading Excel files is:

coef_name.import(type=excel[xml]) source_description [table_description] [variables_description]

The following table_description elements may be used when reading Excel data:

• “range = arg”, where arg is a range of cells to read from the Excel workbook, following the standard Excel format [worksheet!][topleft_cell[:bottomright_cell]].

If the worksheet name contains spaces, it should be placed in single quotes. If the worksheet name is omitted, the cell range is assumed to refer to the currently active sheet. If only a top left cell is provided, a bottom right cell will be chosen automatically to cover the range of non-empty cells adjacent to the specified top left cell. If only a sheet name is provided, the first set of non-empty cells in the top left corner of the chosen worksheet will be selected automatically. As an alternative to specifying an explicit range, a name which has been defined inside the excel workbook to refer to a range or cell may be used to specify the cells to read.

• “byrow”, transpose the incoming data. This option allows you to read files where the series are contained in rows (one row per series) rather than columns.

The optional variables_description may be formed using the elements:

• “colhead=int”, number of table rows to be treated as column headers.

• “na="arg1"”, text used to represent observations that are missing from the file. The text should be enclosed on double quotes.

• “scan=[int| all]”, number of rows of the table to scan during automatic format detection (“scan=all” scans the entire file).

• “firstobs=int”, first observation to be imported from the data (default is 1). This option may be used to start reading rows from partway through the table.

• “lastobs = int”, last observation to be read from the data (default is last observation of the file). This option may be used to read only part of the file, which may be useful for testing.

Excel Examples

coef_obj.import "c:\data files\data.xls"

loads the active sheet of “data.XLSX” into the VEC_NAME vector object.

coef_obj.import "c:\data files\data.xls" range="GDP data"

reads the data contained in the “GDP data” sheet of “data.XLS” into the COEF_OBJ object.

HTML Files

HTML Examples

The syntax for reading HTML pages is:

coef_name.import(type=html) source_description [table_description] [variables_description]

The following table_description elements may be used when reading an HTML file or page:

• “table = arg”, where arg specifies which HTML table to read in an HTML file/page containing multiple tables.

When specifying arg, you should remember that tables are named automatically following the pattern “Table01”, “Table02”, “Table03”, etc. If no table name is specified, the largest table found in the file will be chosen by default. Note that the table numbering may include trivial tables that are part of the HTML content of the file, but would not normally be considered as data tables by a person viewing the page.

• “skip = int”, where int is the number of rows to discard from the top of the HTML table.

• “byrow”, transpose the incoming data. This option allows you to import files where the series are contained in rows (one row per series) rather than columns.

The optional variables_description may be formed using the elements:

• “colhead=int”, number of table rows to be treated as column headers.

• “na="arg1"”, text used to represent observations that are missing from the file. The text should be enclosed on double quotes.

• “scan=[int|all]”, number of rows of the table to scan during automatic format detection (“scan=all” scans the entire file).

• “firstobs=int”, first observation to be imported from the table of data (default is 1). This option may be used to start reading rows from partway through the table.

• “lastobs = int”, last observation to be read from the table of data (default is last observation of the file). This option may be used to read only part of the file, which may be useful for testing.

HTML Examples

coef_obj.import "c:\data.html"

loads into the COEF_OBJ the data located in the HTML file “Data.HTML” located on the C:\ drive

coef_obj.import(type=html) "http://www.tradingroom.com.au/apps/mkt/forex.ac" colhead=3

loads into a coef object called COEF_OBJ the data with the given URL located on the website site “http://www.tradingroom.com.au”. The column header is set to three rows.

Text and Binary Files

Text and Binary File Examples (.txt, .csv, etc.)

The syntax for reading text or binary files is:

coef_name.import(type=arg) source_description [table_description] [variables_description]

If a table_description is not provided, EViews will attempt to read the file as a free-format text file. The following table_description elements may be used when reading a text or binary file:

• “ftype = [ascii|binary]” specifies whether numbers and dates in the file are stored in a human readable text (ASCII), or machine readable (Binary) form.

• “rectype = [crlf|fixed|streamed]” describes the record structure of the file:

“crlf”, each row in the output table is formed using a fixed number of lines from the file (where lines are separated by carriage return/line feed sequences). This is the default setting.

“fixed”, each row in the output table is formed using a fixed number of characters from the file (specified in “reclen= arg”). This setting is typically used for files that contain no line breaks.

“streamed”, each row in the output table is formed by reading a fixed number of fields, skipping across lines if necessary. This option is typically used for files that contain line breaks, but where the line breaks are not relevant to how rows from the data should be formed.

• “reclines =int”, number of lines to use in forming each row when “rectype=crlf” (default is 1).

• “reclen=int”, number of bytes to use in forming each row when “rectype=fixed”.

• “recfields=int”, number of fields to use in forming each row when “rectype=streamed”.

• “skip=int”, number of lines (if rectype is “crlf”) or bytes (if rectype is not “crlf”) to discard from the top of the file.

• “comment=string“, where string is a double-quoted string, specifies one or more characters to treat as a comment indicator. When a comment indicator is found, everything on the line to the right of where the comment indicator starts is ignored.

• “emptylines=[keep|drop]”, specifies whether empty lines should be ignored (“drop”), or treated as valid lines (“keep”) containing missing values. The default is to ignore empty lines.

• “tabwidth=int”, specifies the number of characters between tab stops when tabs are being replaced by spaces (default=8). Note that tabs are automatically replaced by spaces whenever they are not being treated as a field delimiter.

• “fieldtype=[delim|fixed|streamed|undivided]”, specifies the structure of fields within a record:

“Delim”, fields are separated by one or more delimiter characters

“Fixed”, each field is a fixed number of characters

“Streamed”, fields are read from left to right, with each field starting immediately after the previous field ends.

“Undivided”, read entire record as a single series.

• “quotes=[single|double|both|none]”, specifies the character used for quoting fields, where “single” is the apostrophe, “double” is the double quote character, and “both” means that either single or double quotes are allowed (default is “both”). Characters contained within quotes are never treated as delimiters.

• “singlequote“, same as “quotes = single”.

• “custom="arg1"”, specifies custom delimiter characters in the double quoted string. Use the character “t” for tab, “s” for space and “a” for any character.

• “mult=[on|off]”, to treat multiple delimiters as one. Default value is “on” if “delim” is “space”, “dblspace”, “white”, or “dblwhite”, and “off” otherwise.

• “endian = [big|little]”, selects the endianness of numeric fields contained in binary files.

• “string = [nullterm|nullpad|spacepad]”, specifies how strings are stored in binary files. If “nullterm”, strings shorter than the field width are terminated with a single zero character. If “nullpad”, strings shorter than the field width are followed by extra zero characters up to the field width. If “spacepad”, strings shorter than the field width are followed by extra space characters up to the field width.

• “byrow”, transpose the incoming data. This option allows you to import files where the series are contained in rows (one row per series) rather than columns.

• “lastcol”, include implied last column. For lines that end with a delimiter, this option adds an additional column. When importing a CSV file, lines which have the delimiter as the last character (for example: “name, description, date”), EViews normally determines the line to have 3 columns. With the above option, EViews will determine the line to have 4 columns. Note this is not the same as a line containing “name, description, date”. In this case, EViews will always determine the line to have 3 columns regardless if the option is set.

A central component of the table_description element is the format statement. You may specify the data format using the following table descriptors:

• Fortran Format:

fformat=([n1]Type[Width][.Precision], [n2]Type[Width][.Precision], ...)

where Type specifies the underlying data type, and may be one of the following,

I - integer

F - fixed precision

E - scientific

A - alphanumeric

X - skip

and n1, n2, ... are the number of times to read using the descriptor (default=1). More complicated Fortran compatible variations on this format are possible.

• Column Range Format:

rformat="[n1]Type[Width][.Precision], [n2]Type[Width][.Precision], ...)"

where optional type is “$” for string or “#” for number, and n1, n2, n3, n4, etc. are the range of columns containing the data.

• C printf/scanf Format:

cformat="fmt"

where fmt follows standard C language (printf/scanf) format rules.

The optional variables_description may be formed using the elements:

• “colhead=int”, number of table rows to be treated as column headers.

• “na="arg1"”, text used to represent observations that are missing from the file. The text should be enclosed on double quotes.

• “scan=[int|all]”, number of rows of the table to scan during automatic format detection (“scan=all” scans the entire file).

• “firstobs=int”, first observation to be imported from the table of data (default is 1). This option may be used to start reading rows from partway through the table.

Text and Binary File Examples (.txt, .csv, etc.)

coef_obj.import c:\data.csv skip=5

reads “Data.CSV” into a coef_obj, skipping the first 5 rows.

coef_obj.import(type=text) c:\date.txt delim=comma

loads the comma delimited data “Date.TXT” into the COEF_OBJ matrix object.

Cross-references

t=file_type (default=“csv”)	Specifies the file type, where file_type may be: “excelxml” (Excel 2007 (xml)),“csv” (CSV - comma-separated), “rtf” (Rich-text format), “txt” (tab-delimited text), “html” (HTML - Hypertext Markup Language), “emf” (Enhanced Metafile), “pdf” (PDF - Portable Document Format), “tex” (LaTeX), or “md” (Markdown). Files will be saved with the “.xlsx”, “.csv”, “.rtf”, “.txt”, “.htm”, “.emf”, “.pdf”, “.tex”, or “.md” extensions, respectively.
s=arg	Scale size, where arg is from 5 to 200, representing the percentage of the original table size (only valid for HTML or RTF files).
n=string	Replace all cells that contain NA values with the specified string. “NA” is the default.
h / -h	Include(/do not include) column and row headers. The default is to not include the headers
prompt	Force the dialog to appear from within a program.

landscape	Save in landscape mode (the default is to save in portrait mode).
size=arg (default=“letter”)	Page size: “letter”, “legal”, “a4”, and “custom”.
width=number (default=8.5)	Page width in inches if “size=custom”.
height=number (default=11)	Page height in inches if “size=custom”.
leftmargin=number (default=0.5)	Left margin width in inches.
rightmargin=number (default = 0.5)	Right margin width in inches.
topmargin=number (default=1)	Top margin width in inches.
bottommargin= number (default = 1)	Bottom margin width in inches.

mode=arg	Specify whether to create a new file, overwrite an existing file, or update an existing file. arg may be “create” (create new file only; error on attempt to overwrite) or “update” (update an existing file, only overwriting the area specified by the range= table_description). If the “mode=” option is not used, EViews will create a new file, unless the file already exists in which case it will overwrite it. Note that the “mode=update” option is only available for Excel in 1) Excel versions through 2003, if Excel is installed, and 2) Excel 2007 (xml). Note: Excel does not need to be installed for Excel 2007 writing.
cellfmt=arg	Specify whether to use EViews, pre-existing, or remove cell formatting (colors, font, number formatting when possible, column widths and row heights) for the written range. arg may be “eviews” (replace current formatting in the file with the same cell formatting in EViews), “preserve” (leave current cell formatting already in the Excel file), or “clear” (remove current formatting and do not replace).
strlen=arg (default = 256)	Specify the maximum the number of characters written for cells containing text. Strings in cells which are longer the max, will be truncated.

c	Clears all text fields in the label.
d	Sets the description field to text.
s	Sets the source field to text.
u	Sets the units field to text.
r	Appends text to the remarks field as an additional line.
p	Print the label view.

t=dat, txt	ASCII (plain text) files.
t=wk1, wk3	Lotus spreadsheet files.
t=xls	Excel spreadsheet files.

na=text	Specify text for NAs. Default is “NA”.
d=t	Treat tab as delimiter (note: you may specify multiple delimiter options). The default is “d=c” only.
d=c	Treat comma as delimiter.
d=s	Treat space as delimiter.
d=a	Treat alpha numeric characters as delimiter.
custom = symbol	Specify symbol/character to treat as delimiter.
mult	Treat multiple delimiters as one.
rect (default) / norect	[Treat / Do not treat] file layout as rectangular.
skipcol = integer	Number of columns to skip. Must be used with the “rect” option.
skiprow = integer	Number of rows to skip. Must be used with the “rect” option.
comment= symbol	Specify character/symbol to treat as comment sign. Everything to the right of the comment sign is ignored. Must be used with the “rect” option.
singlequote	Strings are in single quotes, not double quotes.
dropstrings	Do not treat strings as NA; simply drop them.
negparen	Treat numbers in parentheses as negative numbers.
allowcomma	Allow commas in numbers (note that using commas as a delimiter takes precedence over this option).

letter_number (default=“b2”)	Coordinate of the upper-left cell containing data.
s=sheet_name	Sheet name for Excel 5–8 Workbooks.

g[.precision]	significant digits
f[.precision]	fixed decimal places
c[.precision]	fixed characters
e[.precision]	scientific/float
p[.precision]	percentage
r[.precision]	fraction

na=string	Specify text string for NAs. Default is “NA”.
d=arg	Specify delimiter (default is tab): “s” (space), “c” (comma).