On 04/13/2017 7:57 AM, Leo May wrote:
> Hi all,
>
> I have done a bit of looking around and havent been able to find any
> other people who have posted the same question. I have seen a few that
> were very similar but I am brand new to Matlab and didn't know how to
> apply those suggestions to my own needs.
>
> I have a table of data, with the first columb denoting the time, and the
> second a voltage value measured at that time.
> I am looking for a way to highlight the voltage values that have a
> difference of more than 50% than the value in the row directly above or
> below. Ideally when I plot these in a graph I would like a comment or
> some way for those values to be pointed out.
dv=abs([1; x(2:end,2)]./x(1:end-1,2)]); % |v(i+1)/v(i)|
in=iswithin(dv,0.5,1.5); % logical vector of in range
hLin=plot(x(in,1),x(in,2)); % those within, save handle to line
hold all
hOut=plot(x(~in,1),x(~in,2),'-*'); % not in, use marker to highlight
The handles to the lines can be used to make other modifications as
desired and to add legends or whatever.
Can also, of course, keep a separate logical for those that are high vs
low and then use color as well as just the marker. Note that in Matlab
graphics each line is a single entity and has only one color and marker
property, etc., for every point on that line; hence the need to PLOT()
twice't...so, to identify high/low/middle, would need the third group/line.
SCATTER() can draw a marker for each point with a color or marker style
for each point but it doesn't incorporate the line.
ISWITHIN() is my "syntactic sugar" utility routine
function flg=iswithin(x,lo,hi)
% returns T for values within range of input
% SYNTAX:
% [log] = iswithin(x,lo,hi)
% returns T for x between lo and hi values, inclusive
flg= (x>=lo) & (x<=hi);
>>
that just moves the logical condition fluff to a lower level aiding in
reading the code...not too tough for a single case such as here, but it
can become extremely useful for multiple conditions or complex logic so
I'll show its use...
--
> Hi all,
>
> I have done a bit of looking around and havent been able to find any
> other people who have posted the same question. I have seen a few that
> were very similar but I am brand new to Matlab and didn't know how to
> apply those suggestions to my own needs.
>
> I have a table of data, with the first columb denoting the time, and the
> second a voltage value measured at that time.
> I am looking for a way to highlight the voltage values that have a
> difference of more than 50% than the value in the row directly above or
> below. Ideally when I plot these in a graph I would like a comment or
> some way for those values to be pointed out.
dv=abs([1; x(2:end,2)]./x(1:end-1,2)]); % |v(i+1)/v(i)|
in=iswithin(dv,0.5,1.5); % logical vector of in range
hLin=plot(x(in,1),x(in,2)); % those within, save handle to line
hold all
hOut=plot(x(~in,1),x(~in,2),'-*'); % not in, use marker to highlight
The handles to the lines can be used to make other modifications as
desired and to add legends or whatever.
Can also, of course, keep a separate logical for those that are high vs
low and then use color as well as just the marker. Note that in Matlab
graphics each line is a single entity and has only one color and marker
property, etc., for every point on that line; hence the need to PLOT()
twice't...so, to identify high/low/middle, would need the third group/line.
SCATTER() can draw a marker for each point with a color or marker style
for each point but it doesn't incorporate the line.
ISWITHIN() is my "syntactic sugar" utility routine
function flg=iswithin(x,lo,hi)
% returns T for values within range of input
% SYNTAX:
% [log] = iswithin(x,lo,hi)
% returns T for x between lo and hi values, inclusive
flg= (x>=lo) & (x<=hi);
>>
that just moves the logical condition fluff to a lower level aiding in
reading the code...not too tough for a single case such as here, but it
can become extremely useful for multiple conditions or complex logic so
I'll show its use...
--
