a — Converts a k-rate parameter to an a-rate value with interpolation.
a(x) (control-rate args only)
where the argument within the parentheses may be an expression. Value converters perform arithmetic translation from units of one kind to units of another. The result can then be a term in a further expression.
Here is an example of the a opcode. It uses the file opa.csd.
Example 42. Example of the a opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform -odac ;;;RT audio out ;-iadc ;;;uncomment -iadc if RT audio input is needed too ; For Non-realtime ouput leave only the line below: ;-o a.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; hear the difference between instr.1 and 2 sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 ;sine wave at k-rate ksig oscil 0.8, 440, 1 ; k-rate to the audio-rate conversion asig = a(ksig) outs asig, asig endin instr 2 ;sine wave at a-rate asig oscil 0.8, 440, 1 outs asig, asig endin </CsInstruments> <CsScore> ; sine wave. f 1 0 16384 10 1 i 1 0 2 i 2 2 2 e </CsScore> </CsoundSynthesizer>
More information on this opcode can be found in the Csound Journal, issue 10, written by Andrés Cabrera.