function [y, t, info, ind_over, ind_under, frames] = wfm2read(filename, datapoints, step, startind)
% function [y, t, info, ind_over, ind_under, frames] = wfm2read(filename, datapoints, step, startind)
%
% loads YT-waveform data from *.wfm file saved by Tektronix TDS5000/B, TDS6000/B/C,
% or TDS/CSA7000/B, MSO70000/C, DSA70000/B/C DPO70000/B/C DPO7000/ MSO/DPO5000
% instrument families into the variables y (y data) and t (time
% data). The structure "info" contains information about units and
% digitizing resolution of the y data. The matrices ind_over and ind_under
% contain the indices of overranged data points outside the upper / lower
% limit of the TDS AD converter.
% If the file contains fast frames data, the data of the first frame is
% stored as usual and of all frames it is stored in the optional
% output struct "frames":
% frames.frame#.y=(y-data of #-th frame, including the first frame again)
% frames.frame#.t
% frames.frame#.info (contains only frame-specific fields of the info structure for frame number #)
% frames.frame#.ind_over
% frames.frame#.ind_under
%
% optional input arguments:
% datapoints, step,startind: read data points startind:step:datapoints
% from the wvf file. if datapoints is omitted, all data are read, if step
% is omitted, step=1. If startind omitted, startind=1
%
% Reading of *.wfm files written by other than the above Oscilloscopes may
% result in errors, since the file format seems not to be downward compatible.
% Other projects exist for the older format, e.g. wfmread.m by Daniel Dolan.
%
% Author:
% Erik Benkler
% Physikalisch-Technische Bundesanstalt
% Section 4.53: Optical Femtosecond Metrology
% Bundesallee 100
% D-38116 Braunschweig
% Germany
% Erik.Benkler a t ptb.de
%
% The implementation is based on Tektronix Article 077-0220-01
% (December 07, 2010): "Performance Oscilloscope Reference Waveform File Format"
% which can be found at:
% http://www2.tek.com/cmswpt/madetails.lotr?ct=MA&cs=mpm&ci=17905&lc=EN
% or by searching for 077022001 on the TEKTRONIX website (the last two
% digits seem to define the revision of the document, so you may search for
% 077922002, 077922003, ... to find newer revisions in future.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% current state of the project and change history:
%
% Version 2.0, 22.03.2011
% (a) added warning IDs for all warnings to render them switchable
% (b) changed behaviour of the "datapoints" input parameter, which now
% defines the number of data points to be returned by wfm2read.
% Added a warning when "datapoints" is too large such that one would
% need more data points in the file / frame.
%
% Version 1.9, December 26, 2010 (re-submitted to FileExchange)
% (a) implemented Fast frames
% (b) added wfm2readframe for reading single frame
% in a fast frames measurement
% (c) Added optional input argument startind, for starting reading at
% this datapoint within each frame
%
% Version 1.8, April 30, 2009 (re-submitted to FileExchange)
% (a) improved file name checking
%
% Version 1.7, January 26, 2009 (re-submitted to FileExchange):
% (a) improved performance when using the step argument by preallocating
% the array
% (b) moved all "unused" read variables to info structure (produces less
% m-lint messages)
%
% Version 1.6, July 23, 2008 (re-submitted to FileExchange):
% (a) Fixed the bug related to default char set on some Linux systems
% pointed out by Markus Kuhn
% (b) Added compatibility with WFM003 format as suggested by Will Fox.
% (the comment in footnote 6 of the SDK on pixmap size has not been
% regarded).
% For a description of the new file format, download and unzip
% http://www.tek.com/products/oscilloscopes/openchoice/SDK_CD_2.0_122
% 72006.zip and look for the file 001137803.pdf in the subdirectory
% bin/Articles/
%
% Version 1.5, December 11, 2005:
% (a) added "step" input argument for reduced data reading.
%
% Version 1.4, November 11, 2005:
% (a) changed to read unit string until NULL string only.
%
% Version 1.3, October 31, 2005 (submitted to FileExchange):
% (a) Added handling of overranged values. Added two output variables
% ind_over and ind_under for this purpose.
%
% Version 1.2, July 07, 2005:
% (a) Added optional second input parameter to limit the number of data
% points to be read.
%
% Version 1.1, April 12, 2005:
% (a) Removed the bug that the byte order verification (big-endian vs. little-endian)
% was disregarded.
% (b) close file at the end.
% (c) Checked functionality with YT-waveform measured with TDS6804B scope.
%
% Version 1.0, December 20, 2004
%
% Already done:
% 1) All file fields listed in the SDK article are assigned to variables named like in the SDK article
% 2) Only reading of YT waveform is implemented. It is assumed that the waveform is
% a simple YT waveform. This is not checked and may result in errors when waveform is other than YT.
% 3) Optional WFM#002 format is implemented (footnote 6 in SDK article)
% 4)Checked functionality with YT-waveform measured with TDS5104B scope
%
% Yet to be done:
% 1) reading of XY-wavefroms etc.
% 2) handle interpolated data
% 3) error checking, e.g. after each file operation, or checking if data is YT waveform should be improved
% 4) only some important header information is output at this stage
% 5) file checksum not yet implemented
% 6) how to handle old format wfm files? Downward compatibility...
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% beginning of code %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%checking of file name etc.
if nargin==0
filename='';
end
if nargin<3
step=1;
end
if nargin<4
startind=1;
end
if isempty(filename)
[fname,pname]=uigetfile({'*.wfm', 'Tektronix Waveform Files (*.wfm)'},'Choose Tektronix WFM file');
filename=[pname fname];
if fname==0 %user pressed Cancel
y=[];
t=[];
ind_over=[];
ind_under=[];
info=[];
frames=[];
return
end
end
[pname,fname] = fileparts(filename);
if isempty(pname)
pname='.';
end
if exist([pname,'\', fname,'.wfm'],'file')~=2
error(['Invalid file name: ' filename]);
end
filename=[pname,'\',fname,'.wfm'];
[fid,message]=fopen(filename);
if fid==-1
error(message);
end
if step<1 || (round(step)~=step)
step=1;
warning('WFM2read:stepPosint',['"step" input parameter must be a positive integer.\nSetting step=1.']);
end
if startind<1 || (round(startind)~=startind)
startind=1;
warning('WFM2read:startindPosint',['"startind" input parameter must be a positive integer.\nSetting startind=1.']);
end
%read the waveform static file info
info.byte_order_verification = dec2hex(fread(fid,1,'uint16'),4);
if strcmp(info.byte_order_verification, '0F0F')
byteorder='l'; % little-endian byte order
else
byteorder='b'; % big-endian byte order
end
info.versioning_number = char(fread(fid,8,'*uint8',byteorder)');
%There's a misprinting in the SDK article, the ":" at the beginning of version number string is missing.
wfm_version = sscanf(info.versioning_number,':WFM#%3d');
if (wfm_version > 3)
warning('WFM2read:HigherVersionNumber','wfm2read has only been tested with WFM file versions <= 3');
end
info.num_digits_in_byte_count = fread(fid,1,'*uint8',byteorder);
info.num_bytes_to_EOF = fread(fid,1,'*int32',byteorder);
info.num_bytes_per_point = fread(fid,1,'uint8',byteorder); %do not convert to same type, since required as double later
info.byte_offset_to_beginning_of_curve_buffer = fread(fid,1,'*uint32',byteorder);
info.horizontal_zoom_scale_factor = fread(fid,1,'*int32',byteorder);
info.horizontal_zoom_position = fread(fid,1,'*float32',byteorder);
info.vertical_zoom_scale_factor = fread(fid,1,'*double',byteorder);
info.vertical_zoom_position = fread(fid,1,'*float32',byteorder);
dummy=fread(fid,32,'*uint8',byteorder);
info.waveform_label = char(dummy(1:find(dummy==0))); %read units until NULL string (suggested by Tom Gaudette)
info.N = fread(fid,1,'*uint32',byteorder);
info.size_of_waveform_header = fread(fid,1,'*uint16',byteorder);
%read waveform header
info.setType = fread(fid,4,'*int8',byteorder);
info.wfmCnt = fread(fid,1,'*uint32',byteorder);
fread(fid,24,'uint8',byteorder); %skip bytes 86 to 109 (not for use)
info.wfm_update_spec_count = fread(fid,1,'*uint32',byteorder);
info.imp_dim_ref_count = fread(fid,1,'*uint32',byteorder);
info.exp_dim_ref_count = fread(fid,1,'*uint32',byteorder);
info.data_type = fread(fid,4,'*int8',byteorder);
fread(fid,16,'uint8',byteorder); %skip bytes 126 to 141 (not for use)
info.curve_ref_count = fread(fid,1,'*uint32',byteorder);
info.num_req_fast_frames = fread(fid,1,'*uint32',byteorder);
info.num_acq_fast_frames = fread(fid,1,'*uint32',byteorder);
%read optional entry in WFM#002 (and higher) file format:
if wfm_version >= 2 % for version number >=2 only
info.summary_frame_type = fread(fid,1,'*uint16',byteorder);
end
info.pixmap_display_format = fread(fid,4,'*int8',byteorder);
info.pixmap_max_value = fread(fid,1,'uint64',byteorder); %storage in a uint64 variable does not work. Uses only double. Bug in Matlab?
%explicit dimension 1
info.ed1.dim_scale = fread(fid,1,'*double',byteorder);
info.ed1.dim_offset = fread(fid,1,'*double',byteorder);
info.ed1.dim_size = fread(fid,1,'*uint32',byteorder);
dummy=fread(fid,20,'*uint8',byteorder);
info.ed1.units = char(dummy(1:find(dummy==0))); %read units until NULL string (suggested by Tom Gaudette)
info.ed1.dim_extent_min = fread(fid,1,'*double',byteorder);
info.ed1.dim_extent_max = fread(fid,1,'*double',byteorder);
info.ed1.dim_resolution = fread(fid,1,'*double',byteorder);
info.ed1.dim_ref_point = fread(fid,1,'*double',byteorder);
info.ed1.format = fread(fid,4,'*int8',byteorder);
info.ed1.storage_type = fread(fid,4,'*int8',byteorder);
info.ed1.n_value = fread(fid,1,'*int32',byteorder);
info.ed1.over_range = fread(fid,1,'*int32',byteorder);
info.ed1.under_range = fread(fid,1,'*int32',byteorder);
info.ed1.high_range = fread(fid,1,'*int32',byteorder);
info.ed1.low_range = fread(fid,1,'*int32',byteorder);
info.ed1.user_scale = fread(fid,1,'*double',byteorder);
info.ed1.user_units = char(fread(fid,20,'*uint8',byteorder)');
ed1.user_offset = fread(fid,1,'*double',byteorder);
% changes suggested by WFox
if wfm_version >= 3
info.ed1.point_density = fread(fid,1,'*double',byteorder);
else
info.ed1.point_density = fread(fid,1,'*uint32',byteorder);
end
% end changes suggested by WFox
info.ed1.href = fread(fid,1,'*double',byteorder);
info.ed1.trig_delay = fread(fid,1,'*double',byteorder);
%explicit dimension 2
info.ed2.dim_scale = fread(fid,1,'*double',byteorder);
info.ed2.dim_offset = fread(fid,1,'*double',byteorder);
info.ed2.dim_size = fread(fid,1,'*uint32',byteorder);
dummy=fread(fid,20,'*uint8',byteorder);
info.ed2.units = char(dummy(1:find(dummy==0))); %read units until NULL string (suggested by Tom Gaudette)
info.ed2.dim_extent_min = fread(fid,1,'*double',byteorder);
info.ed2.dim_extent_max = fread(fid,1,'*double',byteorder);
info.ed2.dim_resolution = fread(fid,1,'*double',byteorder);
info.ed2.dim_ref_point = fread(fid,1,'*double',byteorder);
info.ed2.format = fread(fid,4,'*int8',byteorder);
info.ed2.storage_type = fread(fid,4,'*int8',byteorder);
info.ed2.n_value = fread(fid,1,'*int32',byteorder);
info.ed2.over_range = fread(fid,1,'*int32',byteorder);
info.ed2.under_range = fread(fid,1,'*int32',byteorder);
info.ed2.high_range = fread(fid,1,'*int32',byteorder);
info.ed2.low_range = fread(fid,1,'*int32',byteorder);
info.ed2.user_scale = fread(fid,1,'*double',byteorder);
info.ed2.user_units = char(fread(fid,20,'*uint8',byteorder)');
info.ed2.user_offset = fread(fid,1,'*double',byteorder);
if wfm_version >= 3
info.ed2.point_density = fread(fid,1,'*double',byteorder);
else
info.ed2.point_density = fread(fid,1,'*uint32',byteorder);
end
info.ed2.href = fread(fid,1,'*double',byteorder);
info.ed2.trig_delay = fread(fid,1,'*double',byteorder);
%implicit dimension 1
info.id1.dim_scale = fread(fid,1,'*double',byteorder);
info.id1.dim_offset = fread(fid,1,'*double',byteorder);
info.id1.dim_size = fread(fid,1,'*uint32',byteorder);
info.id1.units = char(fread(fid,20,'*uint8',byteorder)');
info.id1.dim_extent_min = fread(fid,1,'*double',byteorder);
info.id1.dim_extent_max = fread(fid,1,'*double',byteorder);
info.id1.dim_resolution = fread(fid,1,'*double',byteorder);
info.id1.dim_ref_point = fread(fid,1,'*double',byteorder);
info.id1.spacing = fread(fid,1,'*uint32',byteorder);
info.id1.user_scale = fread(fid,1,'*double',byteorder);
info.id1.user_units = char(fread(fid,20,'*uint8',byteorder)');
info.id1.user_offset = fread(fid,1,'*double',byteorder);
if wfm_version >= 3
info.id1.point_density = fread(fid,1,'*double',byteorder);
else
info.id1.point_density = fread(fid,1,'*uint32',byteorder);
end
info.id1.href = fread(fid,1,'*double',byteorder);
info.id1.trig_delay = fread(fid,1,'*double',byteorder);
%implicit dimension 2
info.id2.dim_scale = fread(fid,1,'*double',byteorder);
info.id2.dim_offset = fread(fid,1,'*double',byteorder);
info.id2.dim_size = fread(fid,1,'*uint32',byteorder);
info.id2.units = char(fread(fid,20,'*uint8',byteorder)');
info.id2.dim_extent_min = fread(fid,1,'*double',byteorder);
info.id2.dim_extent_max = fread(fid,1,'*double',byteorder);
info.id2.dim_resolution = fread(fid,1,'*double',byteorder);
info.id2.dim_ref_point = fread(fid,1,'*double',byteorder);
info.id2.spacing = fread(fid,1,'*uint32',byteorder);
info.id2.user_scale = fread(fid,1,'*double',byteorder);
info.id2.user_units = char(fread(fid,20,'*uint8',byteorder)');
info.id2.user_offset = fread(fid,1,'*double',byteorder);
if wfm_version >= 3
info.id2.point_density = fread(fid,1,'*double',byteorder);
else
info.id2.point_density = fread(fid,1,'*uint32',byteorder);
end
info.id2.href = fread(fid,1,'*double',byteorder);
info.id2.trig_delay = fread(fid,1,'*double',byteorder);
%time base 1
info.tb1_real_point_spacing = fread(fid,1,'*uint32',byteorder);
info.tb1_sweep = fread(fid,4,'*int8',byteorder);
info.tb1_type_of_base = fread(fid,4,'*int8',byteorder);
%time base 2
info.tb2_real_point_spacing = fread(fid,1,'*uint32',byteorder);
info.tb2_sweep = fread(fid,4,'*int8',byteorder);
info.tb2_type_of_base = fread(fid,4,'*int8',byteorder);
%wfm update specification (first frame only if fast frames)
info.real_point_offset = fread(fid,1,'*uint32',byteorder);
info.tt_offset = fread(fid,1,'*double',byteorder);
info.frac_sec = fread(fid,1,'*double',byteorder);
info.GMT_sec = fread(fid,1,'*int32',byteorder);
%wfm curve information (first frame only if fast frames)
info.state_flags = fread(fid,1,'*uint32',byteorder);
info.type_of_checksum = fread(fid,4,'*int8',byteorder);
info.checksum = fread(fid,1,'*int16',byteorder);
info.precharge_start_offset = fread(fid,1,'*uint32',byteorder);
info.data_start_offset = fread(fid,1,'uint32',byteorder); %do not convert to same type, since required as double later
info.postcharge_start_offset = fread(fid,1,'uint32',byteorder); %do not convert to same type, since required as double later
info.postcharge_stop_offset = fread(fid,1,'*uint32',byteorder);
info.end_of_curve_buffer_offset = fread(fid,1,'*uint32',byteorder);
if nargout==6 %if output of fast frames data is requested
if info.N>0 %if the file contains fast frame data
%copy data for first frame to the frame struct (I do this to have all
%frames in uniform output structure, although it is clear that this
%uses more memory than minimally needed, i.e. if not copying the data
%of the first frame):
%wfm update specification
frames.('frame1').('info').real_point_offset=info.real_point_offset;
frames.frame1.info.tt_offset=info.tt_offset;
frames.frame1.info.frac_sec=info.frac_sec;
frames.frame1.info.GMT_sec=info.GMT_sec;
%wfm curve information
frames.frame1.info.state_flags=info.state_flags;
frames.frame1.info.type_of_checksum=info.type_of_checksum;
frames.frame1.info.checksum=info.checksum;
frames.frame1.info.precharge_start_offset=info.precharge_start_offset;
frames.frame1.info.data_start_offset=info.data_start_offset;
frames.frame1.info.postcharge_start_offset=info.postcharge_start_offset;
frames.frame1.info.postcharge_stop_offset=info.postcharge_stop_offset;
frames.frame1.info.end_of_curve_buffer_offset=info.end_of_curve_buffer_offset;
%read data for the other frames from the file:
for frm=2:(info.N+1)
%wfm update specification
frames.(['frame' num2str(frm)]).('info').real_point_offset = fread(fid,1,'*uint32',byteorder);
frames.(['frame' num2str(frm)]).info.tt_offset = fread(fid,1,'*double',byteorder);
frames.(['frame' num2str(frm)]).info.frac_sec = fread(fid,1,'*double',byteorder);
frames.(['frame' num2str(frm)]).info.GMT_sec = fread(fid,1,'*int32',byteorder);
end
for frm=2:(info.N+1)
%wfm curve information
frames.(['frame' num2str(frm)]).info.state_flags = fread(fid,1,'*uint32',byteorder);
frames.(['frame' num2str(frm)]).info.type_of_checksum = fread(fid,4,'*int8',byteorder);
frames.(['frame' num2str(frm)]).info.checksum = fread(fid,1,'*int16',byteorder);
frames.(['frame' num2str(frm)]).info.precharge_start_offset = fread(fid,1,'*uint32',byteorder);
frames.(['frame' num2str(frm)]).info.data_start_offset = fread(fid,1,'uint32',byteorder); %do not convert to same type, since required as double later
frames.(['frame' num2str(frm)]).info.postcharge_start_offset = fread(fid,1,'uint32',byteorder); %do not convert to same type, since required as double later
frames.(['frame' num2str(frm)]).info.postcharge_stop_offset = fread(fid,1,'*uint32',byteorder);
frames.(['frame' num2str(frm)]).info.end_of_curve_buffer_offset = fread(fid,1,'*uint32',byteorder);
end
else
frames=[];
end
end
switch info.ed1.format(1) %choose correct data format for reading in curve buffer data
case 0
format='*int16';
case 1
format='*int32';
case 2
format='*uint32';
case 3
format='*uint64'; %may not work properly. Bug in Matlab or not available in 32-bit Windows? Does not convert to uint64, but to double instead.
case 4
format='*float32';
case 5
format='*float64';
case 6
if (wfm_version >= 3)
format='*uint8';
else
error(['invalid data format or error in file ' filename]);
end
case 7
if (wfm_version >= 3)
format='*int8';
else
error(['invalid data format or error in file ' filename]);
end
otherwise
error(['invalid data format or error in file ' filename]);
end
%read the curve data (first frame only if file contains fast frame data)
%jump to the beginning of the curve buffer
offset = double(info.byte_offset_to_beginning_of_curve_buffer+info.data_start_offset+(startind-1)*info.num_bytes_per_point);
byte_offset_nextframe=info.byte_offset_to_beginning_of_curve_buffer+info.end_of_curve_buffer_offset; %byte offset for the next frame (if it exists)
fseek(fid, offset,'bof');
%read the curve buffer portion which is displayed on the scope only
%(i.e. drop precharge and postcharge points)
nop_all=(info.postcharge_start_offset-info.data_start_offset)/info.num_bytes_per_point; %number of data points stored in the file
nop=nop_all-startind+1;
if nargin>=2
if datapoints<1 || (round(datapoints)~=datapoints)
datapoints=floor(nop/step); % set to maximum number of data points which can be securely read from the file, using startind and step parameters
warning('WFM2read:datapointsPosInt',['"datapoints" input parameter must be a positive integer.\nSetting datapoints= ' num2str(datapoints) '.']);
end
nop = floor(nop/step); %maximum number of data points which can be securely read from the frame in the file, using startind and step parameters
if datapoints > nop %if more datapoints are requested than provided in the file
warning('WFM2read:inconsistent_params',['The requested combination of input parameters \n' ...
'datapoints, step and startind would require at least ' num2str(datapoints*step+startind) ' data points in \n'...
fname '\nThe actual number of data points in the trace \nis only ' num2str(nop_all) '. ' ...
'The number of data points returned by wfm2read is thus \n' ...
'only ' num2str(nop) ' instead of ' num2str(datapoints) '.']);
else
nop=datapoints;
end
end
values=double(fread(fid,nop,format,info.num_bytes_per_point*(step-1),byteorder));%#ok %read data values from curve buffer
t = info.id1.dim_offset + info.id1.dim_scale * (startind+(1:step:(nop*step))'-1);
y = info.ed1.dim_offset + info.ed1.dim_scale *values; %scale data values to obtain in correct units
%handling over- and underranged values
ind_over=find(values==info.ed1.over_range); %find indices of values that are larger than the AD measurement range (upper limit)
ind_under=find(values<=-info.ed1.over_range);%find indices of values that are larger than the AD measurement range (lower limit)
info.yunit = info.ed1.units;
info.tunit = info.id1.units;
info.yres = info.ed1.dim_resolution;
info.samplingrate = 1/info.id1.dim_scale;
info.nop = nop;
%print warning if there are wrong values because they are lying outside
%the AD converter digitization window:
if length(ind_over) %#ok
warning('WFM2read:OverRangeValues',[int2str(length(ind_over)), ' over range value(s) in file ' filename]); %#ok
end
if length(ind_under) %#ok
warning('WFM2read:UnderRangeValues',[int2str(length(ind_under)), ' under range value(s) in file ' filename]); %#ok
end
if (info.N>0) && (nargout==6) %if file contains fast frame data and it is requested as output
%copy data for first frame to the frame struct
frames.frame1.y=y;
frames.frame1.t=t;
frames.frame1.ind_over=ind_over;
frames.frame1.ind_under=ind_under;
%get data for all remaining frames:
for frm=2:(info.N+1)
%jump to the beginning of the curve buffer for the current frame
offset = double(byte_offset_nextframe+frames.(['frame' num2str(frm)]).info.data_start_offset+(startind-1)*info.num_bytes_per_point);
byte_offset_nextframe=byte_offset_nextframe+frames.(['frame' num2str(frm)]).info.end_of_curve_buffer_offset; %byte offset for the next frame (if it exists)
%read the curve buffer portion which is displayed on the scope only
%(i.e. drop precharge and postcharge points)
nop_all=(frames.(['frame' num2str(frm)]).info.postcharge_start_offset-frames.(['frame' num2str(frm)]).info.data_start_offset)/info.num_bytes_per_point; %number of data points stored in the frame
fseek(fid, offset,'bof');
nop=nop_all-startind+1;
if nargin>=2
nop = floor(nop/step); %maximum number of data points which can be securely read from the frame in the file, using startind and step parameters
if datapoints > nop %if more datapoints are requested than provided in the file
%don't display warning again for the other frames, it has already been
%displayed for the first frame.
% warning('Wfm2read:inconsistent_params',['The requested combination of input parameters \n' ...
% 'datapoints, step and startind would require at least ' num2str(datapoints*step+startind-1) ' data points in \n'...
% fname '\nThe actual number of data points in the trace \nis only ' num2str(nop_all) '. ' ...
% 'The number of data points returned by wfm2read is thus \n' ...
% 'only ' num2str(nop) ' instead of ' num2str(datapoints) '.']);
else
nop=datapoints;
end
end
values=double(fread(fid,nop,format,info.num_bytes_per_point*(step-1),byteorder));%#ok %read data values from curve buffer
frames.(['frame' num2str(frm)]).y = info.ed1.dim_offset + info.ed1.dim_scale *values; %scale data values to obtain in correct units
frames.(['frame' num2str(frm)]).t = info.id1.dim_offset + info.id1.dim_scale * (startind+(1:step:(nop*step))'-1)-double(info.GMT_sec)-info.frac_sec+double(frames.(['frame' num2str(frm)]).info.GMT_sec)+frames.(['frame' num2str(frm)]).info.frac_sec+(-info.tt_offset+frames.(['frame' num2str(frm)]).info.tt_offset)*info.id1.dim_scale;
%handling over- and underranged values
frames.(['frame' num2str(frm)]).ind_over=find(values==info.ed1.over_range); %find indices of values that are larger than the AD measurement range (upper limit)
frames.(['frame' num2str(frm)]).ind_under=find(values<=-info.ed1.over_range);%find indices of values that are larger than the AD measurement range (lower limit)
%print warning if there are wrong values because they are lying outside
%the AD converter digitization window:
if length(frames.(['frame' num2str(frm)]).ind_over) %#ok
warning('WFM2read:OverRangeValues',[int2str(length(frames.(['frame' num2str(frm)]).ind_over)), ' over range value(s) in file ' filename ', frame ' num2str(frm)]); %#ok
end
if length(frames.(['frame' num2str(frm)]).ind_under) %#ok
warning('WFM2read:UnderRangeValues',[int2str(length(frames.(['frame' num2str(frm)]).ind_under)), ' under range value(s) in file ' filename ', frame ' num2str(frm)]); %#ok
end
end
end
fclose(fid);
