Re: PictureBox max width

Just now received a failure notice from ISP. So resending.

"Mike Williams" <mikea@xxxxxxxxxxxxxxxxx> wrote in message
news:u4Mm8Ww0IHA.4572@xxxxxxxxxxxxxxxxxxxxxxx
"Galen Somerville" <galen@xxxxxxxxxxxxxxxx> wrote in message
news:%236NMDJu0IHA.4336@xxxxxxxxxxxxxxxxxxxxxxx

This has to do with Heart sounds and the ECG. Usually the
height is only 100 to 150 pixels. The length depends on how
many seconds of recording and the rate (usually 2,500 Hz).
Usually we delete bytes at the start so the sound begins right
after the ECG pulse. However many times the sound towards
the end is not good, probably from stehoscope being moved,
etc. So we need to remove bytes from the end of the recording
and that's the length of display problem.

In that case, what I don't understand is why you need to store all this
data as a bitmap representing a "drawn graph" of the ECG data? This is
just data, after all, and you should store it as simple data (an array of
Singles or Longs or Bytes or whatever (depending on the range of values),
with each element of the array representing the voltage or ECG trace value
at each specific point in time. You can then draw the entire graph (or any
part of the graph) onto the display at any time you wish, and you can draw
it in realtime if you wish and at any magnification you desire. There is
no need whatsoever to store the actual bitmap that the data produces.
Using a method such as I have outlined enabled you to store a virtually
inlimited number of data samples, representing a very long "real time"
trace. The only bitmap you ever need to get involved with is the bitmap
that the user can actually see at any one time, which can never be wider
than the display itself.

Mike


The data is stored in simple data arrays. I'm presenting it on the screen as
a scrollable viewport so they can see any part of it.

The problem is erasing a section that could be much wider than the screen
display.

Download the sample program, and a data file, from
http://home.surewest.net/galen/download/resize.zip

When you run it just hit the Return key twice to get to the Menus. Pick
Patient files. then find the file I provided.

Click on Erase button and click anywhere on the upper traces. Now click and
hold the Mouse button down while you move it to the right. When it gets to
the end of the screen you will see that it Continues to scroll.

The moment you release the mouse button it deletes and re-displays.

Galen
P.S. I f you don't want to download an exe file I can put the source code on
the web site.



.