Calculate the memory size the acquired data takes
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Here is a simple data acquisition code:
ai=analoginput('winsound');
addchannel(ai,1);
rate=setverify(ai,'SampleRate',8000);
set(ai,'SamplesPerTrigger',8000);
set(ai,'TriggerType','Immediate');
1. daqmem(ai);
start(ai)
2. daqmem(ai)
stop (ai)
delete ai
clear ai
*1. daqmem(ai): I execute daqmem here, I get:
winsound0-AI
UsedBytes = 30.00 KB
MaxBytes = 1024.00 MB
2. daqmem(ai): I get:
winsound0-AI
UsedBytes = 16.00 KB
MaxBytes = 1024.00 MB*
UsedBytes =30.00KB, what used the memory?
UsedBytes = 16.00 KB, I know it is acquired data, but the totoal number is 8000, which is double type, how to correspond 8000 to 16 KB?
0 commentaires
Réponses (1)
Walter Roberson
le 12 Avr 2014
As speculation: before you have done the start() the internal buffer would be the default, which might be 30 KB. In some ways it makes sense to delay re-sizing the buffer until the next start(), just in case the buffer gets resized yet again (e.g., more channels added.)
winsound normally works internally at 16 bits (2 bytes) per channel, so 8000 samples corresponds to 16000 bytes.
Voir également
Catégories
En savoir plus sur Simultaneous and Synchronized Operations dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!