fvhelpstr.m

matlabDigitalSigalProcess内有文件若干

function str = fvhelpstr(tag,fig)
%FVHELPSTR  Help for Filter Viewer

%   Copyright (c) 1988-98 by The MathWorks, Inc.
% $Revision: 1.7 $

    str{1,1} = 'Filter Viewer';
    str{1,2} = {['No help for this object (' tag ')']};

% ****                       WARNING!                       ****
% ****                                                      ****
% ****  All help text between the SWITCH TAG and OTHERWISE  ****
% ****  statements is automatically generated.  To change   ****
% ****  the help text, edit FVHELP.H and use HWHELPER to    ****
% ****  insert the changes into this file.                  ****

switch tag
case 'help'
str{1,1} = 'FILTER VIEWER';
str{1,2} = {
' '
'This window is a Filter Viewer.  It allows you to view several characteristics of'
'a filter which can be loaded or designed via the SPTool. You can view any'
'combination of the magnitude and phase responses, the group delay, the pole-zero'
'plot, and the impulse and step responses of the filter. Through the Preferences'
'menu item, accessible from the File menu in SPTool, you can customize the layout'
'of the 6 subplots in the Filter Viewer.'
' '
'The Toolbar provides some information about the filter, such as the'
'variable name where the filter is stored (Filter) and the sampling'
'frequency (Fs).  The Toolbar has two zoom buttons that allow you to zoom'
'in and out of each subplot.  It contains a help button which enables you'
'to obtain help on the rest of the Filter Viewer.  It also contains a line'
'selection menu to choose, from the multiple selected filters of the SPTool,'
'which one filter has the ruler focus.  The selected filter''s line color and'
'style can also be changed from this line selection menu.'
' '
'To get help at any time, click once on the Help button.  The mouse pointer'
'becomes an arrow with a question mark symbol.  You can then click on'
'anything in the Filter Viewer, including the options under the menu items,'
'to find out what it is and how to use it.'
};

case 'closemenu'
str{1,1} = 'CLOSE MENU OPTION';
str{1,2} = {
' '
'Select this menu option to close the Filter Viewer.'
};

case 'mainframe'
str{1,1} = 'MAIN FRAME';
str{1,2} = {
' '
'In this region of the Filter Viewer, you can select which subplots to'
'display in the main window, set the scaling of various subplot axes, and'
'set the sampling frequency.'
};

case {'plotframe','plottext'}
str{1,1} = 'PLOTS FRAME';
str{1,2} = {
' '
'This frame indicates which subplots are currently displayed in the main'
'window to the right.  You can enable some or all of the plots.  Simply'
'check the corresponding box to enable a plot.  You can choose from:'
'magnitude response, phase response, group delay, pole-zero plot, impulse'
'response, and step response.'
};

case 'magcheck'
str{1,1} = 'MAGNITUDE';
str{1,2} = {
' '
'Check this box to enable the magnitude response subplot.  '
};

case {'maglist','magframe'}
str{1,1} = 'MAG SCALING';
str{1,2} = {
' '
'You can choose a scaling for the magnitude plot (linear, log, or decibels)'
'by choosing from the Magnitude popup menu.'
};

case 'phasecheck'
str{1,1} = 'PHASE';
str{1,2} = {
' '
'Check this box to enable the phase response subplot.'
};

case {'phaselist','phaseframe'}
str{1,1} = 'PHASE UNITS';
str{1,2} = {
' '
'You can choose the units for the phase (degrees or radians) by choosing'
'from the Phase popup menu.'
};

case 'groupdelay'
str{1,1} = 'GROUP DELAY';
str{1,2} = {
' '
'Check this box to enable the group delay subplot.  The group delay is'
'defined as the derivative of the phase response.'
};

case 'polezero'
str{1,1} = 'POLE-ZERO';
str{1,2} = {
' '
'Check this box to enable the pole-zero subplot.  This displays the poles'
'and zeros of the transfer function and their proximity to the unit circle.'
};

case 'impresp'
str{1,1} = 'IMPULSE RESP.';
str{1,2} = {
' '
'Check this box to enable the impulse response subplot.  This displays the'
'result of applying the filter to a discrete-time unit-height impulse at 0.'
};

case 'stepresp'
str{1,1} = 'STEP RESPONSE';
str{1,2} = {
' '
'Check this box to enable the step response subplot.  This displays the'
'result of applying the filter to a discrete-time unit-height step at 0.'
};

case {'freqframe','freqtext'}
str{1,1} = 'FREQUENCY AXIS';
str{1,2} = {
' '
'In this frame, you can set the scaling and range of the frequency axis.'
};

case {'freqsframe','freqscale','freqstext'}
str{1,1} = 'FREQ. SCALING';
str{1,2} = {
' '
'You can choose the scaling for the frequency axis (linear or log) by'
'selecting the appropriate option from this popup menu.'
};

case {'freqrframe','freqrange','freqrtext'}
str{1,1} = 'FREQ. RANGE';
str{1,2} = {
' '
'You can choose the range for the frequency axis by selecting an option from'
'this popup menu.  The options are [0, Fs/2], [0, Fs], and [-Fs/2, Fs/2],'
'where Fs in the sampling frequency displayed in the upper left-hand corner'
'of the Filter Viewer in the Toolbar.'
};

case 'toolbar'
str{1,1} = 'TOOLBAR';
str{1,2} = {
' '
'The Toolbar has four sections.  On the left it has two variables, Filter'
'and Fs, which provide filter information.  Following the two variables are'
'two zoom buttons.  On the right side of the Toolbar there is a help button'
'followed by a line selection menu to choose, from the multiple selected'
'filters of the SPTool, which one filter has the ruler focus.  The selected'
'filter''s line color and style can also be changed from this line selection'
'menu.'
' '
'The two variables, Filter and Fs, contain the filter name and its sampling'
'frequency, respectively, of the filter design currently selected. You can'
'change these using the edit menu of the SPTool.  When viewing multiple'
'filters which don''t all have the same sampling frequency the largest'
'sampling frequency will be used.  Also, when viewing multiple filters where'
'the names of all the selected filters do not fit in the allowed space the'
'number of filters selected will be displayed instead of the names of the'
'individual filters selected.'
};

case 'fvzoom:mousezoom'
str{1,1} = 'MOUSE ZOOM';
str{1,2} = {
' '
'Clicking this button puts you in "Mouse Zoom" mode. In this mode, the mouse'
'pointer becomes a cross when it is inside any of the six subplot areas.'
'You can click and drag a rectangle in a subplot, and the axes display will'
'zoom in to that region.  If you click with the left button at a point in a'
'subplot, the axes display will zoom in to that point for a more detailed'
'look at the data at that point.  Similarly, you can click with the right'
'mouse button (shift click on a Mac) at a point in a subplot to zoom out'
'from that point for a wider view of the data.'
' '
'To get out of the mouse zoom mode without zooming in or out, click on the'
'Mouse Zoom button again.'
' '
'ZOOM PERSISTENCE'
' '
'Normally you leave zoom mode as soon as you zoom in or out once.  In order'
'to zoom in or out again, the Mouse Zoom button must be clicked again.'
'However, the mouse zoom mode will remain enabled after a zoom if the box'
'labeled ''Stay in Zoom Mode after Zoom'' is checked in the Preferences for'
'SPTool window.  The Preferences for SPTool window can be opened by'
'selecting Preferences under the File menu in SPTool.'
};

case 'fvzoom:zoomout'
str{1,1} = 'FULL VIEW';
str{1,2} = {
' '
'Clicking this button restores the axes limits of all the subplots.'
};

case 'magaxes'
str{1,1} = 'MAGNITUDE';
str{1,2} = {
' '
'This axes displays the magnitude of the frequency response of the currently'
'selected filters.'
};

case 'phaseaxes'
str{1,1} = 'PHASE';
str{1,2} = {
' '
'This axes displays the phase of the frequency response of the currently'
'selected filters.'
};

case 'delayaxes'
str{1,1} = 'GROUP DELAY';
str{1,2} = {
' '
'This axes displays the group delay (defined as the derivative of the phase'
'of the frequency response) of the currently selected filters.'
};

case 'pzaxes'
str{1,1} = 'POLE-ZERO';
str{1,2} = {
' '
'This axes displays the poles and zeros of the transfer function of the'
'currently selected filters in relationship to the unit circle.'
};

case 'impaxes'
str{1,1} = 'IMPULSE RESPONSE';
str{1,2} = {
' '
'This axes displays the response of the currently selected filters to a'
'discrete-time unit-height impulse at 0.'
};

case 'stepaxes'
str{1,1} = 'STEP RESPONSE';
str{1,2} = {
' '
'This axes displays the response of the currently selected filters to a'
'discrete-time unit-height step function.'
};

case 'magline'
str{1,1} = 'MAGNITUDE RESP.';
str{1,2} = {
' '
'This line is the magnitude of the frequency response of one of the'
'currently selected filters.  When not in mouse zoom mode, you can click and'
'drag on the response to move it around this subplot.'
};

case 'phaseline'
str{1,1} = 'PHASE RESPONSE';
str{1,2} = {
' '
'This line is the phase of the frequency response of one of the currently'
'selected filters.  When not in mouse zoom mode, you can click and drag on'
'the response to move it around this subplot.'
};

case 'delayline'
str{1,1} = 'GROUP DELAY';
str{1,2} = {
' '
'This line is the group delay (defined as the derivative of the phase of the'
'frequency response) of the currently selected filters.  When not in mouse'
'zoom mode, you can click and drag on the line to move it around this'
'subplot.'
};

case {'implinedots','implinestem'}
str{1,1} = 'IMPULSE RESP.';
str{1,2} = {
' '
'This stem plot is the response of the currently selected filters to a'
'discrete-time unit-height impulse at 0.  When not in mouse zoom mode, you'
'can click and drag on the response to move it around this subplot.'
};

case {'steplinedots','steplinestem'}
str{1,1} = 'STEP RESPONSE';
str{1,2} = {
' '
'This stem plot is the response of the currently selected filters to a'
'discrete-time unit-height step function.  When not in mouse zoom mode, you'
'can click and drag on the response to move it around this subplot.'
};

case 'polesline'
str{1,1} = 'POLE';
str{1,2} = {
' '
'This ''x'' represents a pole of the transfer function of the current'
'filter.'
};

case 'zerosline'
str{1,1} = 'ZERO';
str{1,2} = {
' '
'This ''o'' represents a zero of the transfer function of one of the currently'
'selected filters.'
};

case 'unitcircle'
str{1,1} = 'UNIT CIRCLE';
str{1,2} = {
' '
'This dotted line is the unit circle.  Depending on the type of filter,'
'the proximity of the poles and zeros to the unit circle may yield'