- — Subtraction operator.
Arithmetic operators perform operations of change-sign (negate), don't-change-sign, logical AND logical OR, add, subtract, multiply and divide. Note that a value or an expression may fall between two of these operators, either of which could take it as its left or right argument, as in
a + b * c.
In such cases three rules apply:
1. * and / bind to their neighbors more strongly than + and −. Thus the above expression is taken as
a + (b * c)
with * taking b and c and then + taking a and b * c.
2. + and − bind more strongly than &&, which in turn is stronger than ||:
a && b - c || d
is taken as
(a && (b - c)) || d
3. When both operators bind equally strongly, the operations are done left to right:
a - b - c
is taken as
(a - b) - c
Parentheses may be used as above to force particular groupings.
−a (no rate restriction)
a − b (no rate restriction)
where the arguments a and b may be further expressions.
The arguments of − can be scalar values or k-rate one dimensional arrays (vectors), or any combination. If one of the arguments is an array, so is the value.
Here is an example of the - operator. It uses the file subtracts.csd.
Example 28. Example of the - operator.
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 ; Audio out Audio in No messages -odac ;;;realtime audio I/O ; For Non-realtime ouput leave only the line below: ; -o -.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 idur = p3 iatt = p4 idec = p5 isus = p3-iatt-idec ;calculate sustain time from subtracting attack and decay printf_i "sutain time= note duration - attack - decay --> %.1f-%.1f-%.1f = %.1f\n", 1, idur, iatt, idec, isus kenv expseg 0.01, iatt, 1, isus, 1, idec, 0.01 ;envelope asig poscil 1*kenv, 200, 1 outs asig, asig endin </CsInstruments> <CsScore> f 1 0 4096 10 1 ;sine wave ; attack decay i 1 0 3 .1 .2 i 1 4 3 .5 1.5 i 1 8 5 4 .5 e </CsScore> </CsoundSynthesizer>
Its output should include lines like these:
sutain time= note duration - attack - decay --> 3.0-0.1-0.2 = 2.7 sutain time= note duration - attack - decay --> 3.0-0.5-1.5 = 1.0 sutain time= note duration - attack - decay --> 5.0-4.0-0.5 = 0.5