RFILE_f
=======

Read from input file



Block Screenshot
~~~~~~~~~~~~~~~~





Contents
~~~~~~~~


+ `Read from input file`_
  +

    + `Palette`_
    + `Description`_
    + `Data types`_
    + `Dialog box`_
    + `Default properties`_
    + `Example`_
    + `Interfacing function`_
    + `Computational function`_
    + `See also`_





Palette
~~~~~~~


+ `Sources palette`_




Description
~~~~~~~~~~~

This block allows user to read data in a file with the name defined
with the **Input File Name** parameter, in text formatted mode or in
binary mode.

The file is a sequence of records. Each record has the length **Record
Size** `+ 1` and the structure shown below:



The **Time Record Selection** parameter allows to user the selection
of one field in the record which represents time events. When this
parameter is set, an activation output is added to the block to return
these events to the user. With a feedback of the activation output to
the event input of the block, the records are read in sequence until
file end as in the example below.

The **Outputs Record Selection** is used to select the record's fields
which will be included in the regular output.

The **Output Format** parameter gives the record format.


+ For a binary file, this parameter is an empty string.
+ For a text file, this parameter is a string of format (Fortran
  syntax) enclosed by parentheses.


Each event on the activation input of the block advances one record in
the file.



Data types
~~~~~~~~~~


+ Output: a scalar or a column vector of data of type double. The
  vector length is equal to the length of the **Outputs Record
  Selection** vector.




Dialog box
~~~~~~~~~~






+ **Time record selection** An empty matrix or a positive integer. If
  an integer * `i`* is given the * `i th `* element of the read record
  is assumed to be the date of the output event. If it is an empty
  matrice, no output event exists. Properties : Type 'vec' of size -1.
+ **Outputs record selection** A vector of positive integer * `[k i
  ,...,k n ]`* the element * `k i th `* of the read record gives the
  value of the * `i th `* output. Properties : Type 'vec' of size -1.
+ **Input file name** A character string defining the path of the
  file. The block support file name expansion and you can use
  environment variables like *PWD* in the path, by example
  *"PWD/my_data/"*. Without path specifier, the file is read in the
  directory defined by the *PWD* variable. The file must exist,
  otherwise you will be prompted by an error message. Properties : Type
  'str' of size 1.
+ **Input Format** A character string defining the Fortran format to
  use or nothing for an unformatted (binary) write. If given, the format
  must began by a left parenthesis and end by a right parenthesis.
  Example: * `(10e3)`* Properties : Type 'str' of size 1.
+ **Buffer size** To improve efficiency it is possible to buffer the
  input data. The reading of samples on the peripheral fills the buffer
  so that there are always available data in memory for the block.
  Properties : Type 'vec' of size 1.




Default properties
~~~~~~~~~~~~~~~~~~


+ **always active:** no
+ **direct-feedthrough:** no
+ **zero-crossing:** no
+ **mode:** no
+ **regular outputs:** **- port 1 : size [1,1] / type 1**
+ **number/sizes of activation inputs:** 1
+ **number/sizes of activation outputs:** 0
+ **continuous-time state:** no
+ **discrete-time state:** yes
+ **object discrete-time state:** no
+ **name of computational function:** readf




Example
~~~~~~~

This example reads the file:
*"SCI/modules/xcos/examples/sources_pal/en_US/rfile_f.txt"* which
contains a set of data generated by the example of the `WFILE_f`_
block help page.

It use its activation output as event input of CSCOPE. In the file,
the first field of the record is the time, the two others are regular
data. The feedback of the activation output on event input ensures the
file sequential read. `Open this example in Xcos`_ .





Interfacing function
~~~~~~~~~~~~~~~~~~~~


+ `SCI/modules/scicos_blocks/macros/Sources/RFILE_f.sci`_




Computational function
~~~~~~~~~~~~~~~~~~~~~~


+ SCI/modules/scicos_blocks/src/fortran/readf.f (Type 0)




See also
~~~~~~~~


+ `WFILE_f`_ Write to output file
+ `READC_f`_ Read binary data
+ `WRITEC_f`_ Write to C binary file


.. _Dialog box: RFILE_f.html#Dialogbox_RFILE_f
.. _Computational function: RFILE_f.html#Computationalfunction_RFILE_f
.. _READC_f: READC_f.html
.. _WFILE_f: WFILE_f.html
.. _Read from input file: RFILE_f.html
.. _Open this example in Xcos: nullscilab.xcos/xcos/examples/sources_pal/en_US/rfile_f_en_US.xcos
.. _SCI/modules/scicos_blocks/macros/Sources/RFILE_f.sci: nullscilab.scinotes/scicos_blocks/macros/Sources/RFILE_f.sci
.. _Data types: RFILE_f.html#Datatype_RFILE_f
.. _Palette: RFILE_f.html#Palette_RFILE_f
.. _Example: RFILE_f.html#Example_RFILE_f
.. _Sources palette: Sources_pal.html
.. _WRITEC_f: WRITEC_f.html
.. _Interfacing function: RFILE_f.html#Interfacingfunction_RFILE_f
.. _Default properties: RFILE_f.html#Defaultproperties_RFILE_f
.. _See also: RFILE_f.html#Seealso_RFILE_f
.. _Description: RFILE_f.html#Description_RFILE_f