path: root/desiredata/extra/help-expr.pd

#N canvas 70 36 1012 579 10;
#X text 66 10 expression evaluation family - expr \, expr~ \, fexpr~
;
#X text 63 239 Syntyax:;
#X text 64 311 $f#: float input variable;
#X text 65 326 $s#: symbol input variable;
#X text 553 90 Used for expr~ only:;
#X text 553 105 $v#: signal (vector) input (vector by vector evaluation)
;
#X text 550 164 Used for fexpr~ only:;
#X text 550 220 $y[n]: the output value indexed by n where n has to
satisfy 0 > n >= -vector size.;
#X text 550 248 (the vector size can be changed by the "block~" object.)
;
#X text 550 179 $x#[n]: the sample from inlet # indexed by n where
n has to satisfy 0 => n >= -vector size \, ($x# is a shorthand for
$x#[0] \, specifying the current sample);
#X text 63 151 expr~ is used for expression evaluaion of signal data
on the vector by vector basis;
#X text 63 136 expr is used for expression evaluaion of control data
;
#X text 67 39 For a more detailed documentaion refer to http://www.crca.ucsd.edu/~yadegari/expr.html
;
#X text 64 254 The syntax is very close to how expressions are written
in C. Variables are specified as follows where the '#' stands for the
inlet number:;
#X text 65 297 $i#: integer input variable;
#X text 63 179 fexpr~ is used for expression evaluaion on sample level
data \; i.e. \, filter design. Warning: fexpr~ is very cpu intensive.
;
#X text 633 12 updated for Pd 0.35 test 26 and expr* 0.4;
#X text 67 85 you can define multiple expressoins in the same object.
semicolon is used to separates the expressions.;
#X text 635 294 $y -> $y1[-1];
#X text 550 263 Shorthands: $x -> $x1[0];
#X text 635 279 $x1 -> $x1[0] $x2 -> $x2[0] .....;
#X text 635 309 $y1 -> $y1[-1] $y2 -> $y2[-1] .....;
#N canvas 0 0 828 385 Examples 0;
#X obj 33 151 expr 1;
#X floatatom 197 119 0 0 0;
#X floatatom 33 181 0 0 0;
#X msg 33 123 bang;
#X obj 101 149 expr 2 + 3;
#X msg 101 122 bang;
#X floatatom 101 177 0 0 0;
#X floatatom 196 177 0 0 0;
#X obj 196 149 expr 2+$f1;
#X floatatom 34 220 0 0 0;
#X floatatom 34 277 0 0 0;
#X obj 34 249 expr $f1 * $f2;
#X floatatom 113 220 0 0 0;
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#X array array1 10 float 0;
#X coords 0 10 10 0 200 150 1;
#X restore 584 180 graph;
#X floatatom 35 315 0 0 0;
#X floatatom 35 371 0 0 0;
#X floatatom 194 219 0 0 0;
#X floatatom 194 276 0 0 0;
#X obj 194 248 expr $s2[$f1];
#X msg 267 220 symbol array1;
#X obj 35 343 expr sin(2 * 3.14159 * $f1 / 360);
#X msg 330 281 \; array1 1 4 2 8 5 6 1 4 2 8 5 6;
#X floatatom 310 184 5 0 0;
#X floatatom 395 186 5 0 0;
#X floatatom 480 184 5 0 0;
#X floatatom 310 105 5 0 0;
#X obj 310 132 expr $f1 \; if ($f1 > 0 \, $f1 * 2 \, 0) \; if ($f1
<= 0 \, $f1 / 2 \, 0);
#X text 34 56 Examples of expr object;
#X text 304 88 an example of multiple expressions and the use of 'if'
;
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#X restore 307 398 pd Examples of expr;
#N canvas 23 24 882 676 Examples 0;
#X text -88 101 expr~ examples:;
#X obj -24 355 print~;
#X msg 13 334 bang;
#X obj -24 276 sig~ 440;
#X floatatom 49 293 0 0 0;
#X floatatom -24 253 0 0 0;
#X obj -24 316 expr~ $v1*$f2;
#X obj 85 356 print~;
#X msg 101 335 bang;
#X floatatom 85 268 0 0 0;
#X floatatom 158 270 0 0 0;
#X floatatom 357 291 0 0 0;
#X floatatom 244 267 0 0 0;
#X obj 244 294 osc~;
#X msg 369 47 \; pd dsp 0;
#X msg 291 49 \; pd dsp 1;
#X text 294 26 audio on;
#X text 377 25 audio off;
#X text -45 236 vector times scalar;
#X text 87 236 vector;
#X obj 243 354 dac~;
#X text 241 245 frequency;
#X text 373 273 amplitude;
#X obj 85 315 expr~ $v1*$v2;
#X floatatom 207 471 5 0 0;
#X obj -40 520 tabsend~ a1;
#N canvas 0 0 450 300 graph4 0;
#X array a1 64 float 0;
#X coords 0 1 63 -1 200 140 1;
#X restore -39 542 graph;
#X obj -40 497 expr~ max(min($v1 \, $f2/10) \, -$f2/10);
#X text -38 123 NOTES: the first inlet of expr~ cannot be a $f1 or
$i1 \, this may change in later releases;
#X text -87 420 A simple limiter example;
#X obj 356 158 vsl 15 128 0 127 0 0 empty empty empty 20 8 0 8 -262144
-1 -1 0 1;
#X obj 243 315 expr~ $v1*$f2/128;
#X text -82 28 make sure you turn on audio for the expr~ examples;
#X obj -40 473 osc~ 2756.25;
#X text 122 436 Move the value below between 0 and 10;
#X text 126 451 to change the limiter threshold;
#X obj 417 522 tabsend~ a2;
#X obj 580 518 tabsend~ a3;
#X obj 417 439 osc~ 2756.25;
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#X array a2 64 float 1;
#A 0 -0.419198 -0.487122 -0.481805 -0.400382 -0.252053 -0.0571681 0.155563
0.353314 0.504227 0.582557 0.573016 0.473664 0.296682 0.0669659 -0.18137
-0.410083 -0.582709 -0.670415 -0.656787 -0.540803 -0.337462 -0.0758923
0.204826 0.461522 0.653623 0.74958 0.732042 0.600932 0.373867 0.0838359
-0.225617 -0.506972 -0.716061 -0.819026 -0.797803 -0.653251 -0.405409
-0.0906877 0.243486 0.545852 0.769218 0.877835 0.853191 0.697093 0.431698
0.096368 -0.258195 -0.577642 -0.812367 -0.925245 -0.897515 -0.731894
-0.452386 -0.100793 0.269551 0.601932 0.844984 0.960659 0.930205 0.757204
0.467199 0.103913 -0.277405 -0.618414;
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#X restore 347 554 graph;
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#X array a3 64 float 0;
#X coords 0 1 63 -1 200 140 1;
#X restore 569 554 graph;
#X obj 417 473 expr~ $v1 *$v2 \; if ($v2 > 0 \, 0 \, $v1*$v2);
#X obj 580 439 osc~ 100;
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#X restore 307 433 pd Examples of expr~;
#X text 40 399 For expr examples click here ->;
#X text 41 433 For expr~ examples click here ->;
#X text 40 471 For fexpr~ examples click here ->;
#N canvas 0 0 1059 688 examples 0;
#X msg 519 84 \; pd dsp 0;
#X msg 428 84 \; pd dsp 1;
#X text 426 64 audio on;
#X text 518 65 audio off;
#X floatatom 126 304 0 0 0;
#X floatatom 259 323 0 0 0;
#X msg 226 283 -10;
#X text 53 103 fexpr~ examples:;
#X obj 125 571 print~;
#X msg 247 552 bang;
#X floatatom 125 475 0 0 0;
#X obj 126 347 fexpr~ ($x1[$f2]+$x1)/2;
#X obj 125 532 fexpr~ $x1+$y[-1];
#X floatatom 635 366 0 0 0;
#X floatatom 795 387 0 0 0;
#X obj 630 456 dac~;
#X obj 632 407 fexpr~ ($x1[$f2/1000]+$x1)/2;
#X msg 864 317 0 10000;
#X obj 795 368 line 0;
#X msg 798 318 -10000;
#X obj 120 389 dac~;
#X text 96 227 Simple FIR filter;
#X text 557 134 Simple FIR filter using fractional offset;
#X msg 704 318 -10000 10000;
#X obj 635 387 osc~ 2205;
#X msg 644 343 1102.5;
#X msg 862 342 0 10000;
#X msg 796 343 -20000;
#X msg 702 343 -20000 10000;
#X msg 635 318 2205;
#X msg 548 312 start;
#X msg 550 334 stop;
#X msg 57 284 start;
#X msg 56 309 stop;
#X msg 75 469 start;
#X msg 74 494 stop;
#X obj 491 335 loadbang;
#X obj 18 495 loadbang;
#X obj 1 309 loadbang;
#X text 617 291 frequency;
#X text 707 300 of the simple filter;
#X msg 293 282 -20;
#X obj 126 325 osc~ 2205;
#X msg 156 281 1102.5;
#X msg 110 281 2205;
#X msg 260 282 0;
#X text 123 445 simple accumulator defined as and an IIR filter;
#X text 52 148 NOTE: fexpr~ could use lots of CPU power \, by default
fexpr~ is on when it is loaded. In this page we are turning them off
with loadbang \, so to hear them you have to turn them on explicitly.
You can use the "start" and "stop" messages to start and stop fexpr~
and expr~;
#X text 706 288 index defining the frequency;
#X text 95 240 -10 offset will fully filter audio frequency of 2205
\, and -20 offset will filter audio at frequency of 1102.5;
#X text 559 215 Thus \, the offset -10000 will filter audio at frequency
of 2205 and the offset value -20000 will filter the audio at frequency
of 1102.5.;
#X text 558 161 When fractional offset is used \, fexpr~ determines
indexed by linear interpolation. In the following example the offset
value is divided by 1000 \, thus we can continuously change the offset
without an audible click in the output.;
#X text 288 318 If you change this value you;
#X text 290 330 hear a click;
#X text 51 87 make sure you turn on audio for the fexpr~ examples;
#X text 55 -323 Used for fexpr~ only:;
#X text 55 -267 $y[n]: the output value indexed by n where n has to
satisfy 0 > n >= -vector size.;
#X text 55 -239 (the vector size can be changed by the "block~" object.)
;
#X text 55 -308 $x#[n]: the sample from inlet # indexed by n where
n has to satisfy 0 => n >= -vector size \, ($x# is a shorthand for
$x#[0] \, specifying the current sample);
#X text 140 -193 $y -> $y1[-1];
#X text 55 -224 Shorthands: $x -> $x1[0];
#X text 140 -208 $x1 -> $x1[0] $x2 -> $x2[0] .....;
#X text 140 -178 $y1 -> $y1[-1] $y2 -> $y2[-1] .....;
#X text 64 -125 fexpr~ responds to the following methods;
#X text 66 -106 clear - clears all the previous input and output buffers
;
#X text 65 -92 clear x# - clears the previous values of the #th input
;
#X text 66 -79 clear y# - clears the previous values of the #th output
;
#X text 66 -33 set x# val-1 val-2 ... - sets the as many supplied values
of the #th input;
#X text 513 -22 e.g. \, set x2 3.4 0.4 sets x2[-1]=3.4 and x2[-2]=0.4
;
#X text 66 -2 set y# val-1 val-2 ... - sets the as many supplied values
of the #th input;
#X text 514 4 e.g. \, set y3 1.1 3.3 4.5 sets y3[-1]=1.1 y3[-2]=3.3
and y3[-3]=4.5;
#X text 64 -54 set val val ... - sets the first past values of each
output;
#X text 513 -59 e.g. \, set 0.1 2.2 0.4 sets y1[-1]=0.1 y2[-1]=2.2
\, and y3[-1]=0.4;
#X msg 244 475 set 4000;
#X obj 125 504 sig~ 0.001;
#X msg 245 498 clear;
#X text 22 442 comment;
#X text 14 431 1 first click the start button;
#X text 307 494 2 click the set or the clear button;
#X text 304 547 3 then click bang to see how set and clear work;
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#X restore 306 472 pd examples of fexpr~;
#X text 42 504 For using fexpr~ for solving;
#X text 43 520 differential equations click here ->;
#N canvas 112 22 944 449 lorenz 0;
#X obj 176 67 v pr;
#X obj 307 68 v r;
#X obj 233 69 v b;
#X floatatom 176 38 5 0 0;
#X floatatom 307 40 5 0 0;
#X msg 177 13 10;
#X obj 231 10 expr 8./3;
#X msg 128 136 set 1.2 2.3 4.4;
#X floatatom 233 39 7 0 0;
#X msg 75 46 stop;
#X msg 75 67 start;
#X floatatom 399 40 5 0 0;
#X obj 399 69 v dt;
#X msg 310 12 18;
#X msg 395 13 0.01;
#X obj 68 296 dac~;
#X obj 128 -41 bng 15 250 50 0 empty empty empty 20 8 0 8 -262144 -1
-1;
#X text 201 -41 <- turn audio on and bang here;
#X text 463 42 <- experiment with these numbers;
#X text 472 72 if you hear a buzz \, you have probably gone unstable
bang on the top again;
#X obj 489 15 line;
#X obj 128 241 /~ 20;
#X obj 234 238 /~ 20;
#X obj 340 237 /~ 20;
#X msg 484 -11 0.01 \, 0.04 5000;
#X obj 128 185 fexpr~ $y1+(pr*$y2-pr*$y1)*dt \; $y2 +(-$y1*$y3 + r*$y1-$y2)*dt
\; $y3+($y1*$y2 - b*$y3)*dt;
#X obj 14 65 loadbang;
#X text 113 -100 This is an example of how fexpr~ could be used for
solving differential equations \, in this case the lorenz equations
which generate chotic signals;
#X text 361 182 Note the following shorthands:;
#X text 360 198 $y1 -> $y1[-1] \, $y2 -> $y2[-1] \, .....;
#X text 248 136 the 'set' commands sets the initial previous values
;
#X obj 128 298 tabsend~ lorenz1a;
#X obj 234 278 tabsend~ lorenz2a;
#X obj 339 259 tabsend~ lorenz3a;
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#X array lorenz3a 64 float 0;
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#X restore 592 436 graph;
#X text 301 315 You can see the graphs if you scroll down;
#X text 301 328 but the redrawings may cause clicks in the audio;
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#X restore 308 518 pd lorenz equations for audition;
#N canvas 97 36 978 656 lorenz 0;
#X obj 176 67 v pr;
#X obj 307 68 v r;
#X obj 233 69 v b;
#X floatatom 176 38 5 0 0;
#X floatatom 307 40 5 0 0;
#X msg 177 13 10;
#X obj 231 10 expr 8./3;
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#X restore 82 357 graph;
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#X array lorenz3 2048 float 0;
#X coords 0 -1 2047 1 200 140 1;
#X restore 570 347 graph;
#X msg 128 136 set 1.2 2.3 4.4;
#X floatatom 233 39 7 0 0;
#X msg 75 46 stop;
#X msg 75 67 start;
#X floatatom 399 40 5 0 0;
#X obj 399 69 v dt;
#X msg 310 12 18;
#X msg 395 13 0.01;
#X obj 128 -41 bng 15 250 50 0 empty empty empty 20 8 0 8 -262144 -1
-1;
#X text 201 -41 <- turn audio on and bang here;
#X text 463 42 <- experiment with these numbers;
#X text 472 72 if you hear a buzz \, you have probably gone unstable
bang on the top again;
#X obj 489 15 line;
#X obj 128 241 /~ 20;
#X obj 234 238 /~ 20;
#X obj 340 237 /~ 20;
#X msg 484 -11 0.01 \, 0.04 5000;
#X obj 14 65 loadbang;
#X text 113 -100 This is an example of how fexpr~ could be used for
solving differential equations \, in this case the lorenz equations
which generate chotic signals;
#X text 361 182 Note the following shorthands:;
#X text 360 198 $y1 -> $y1[-1] \, $y2 -> $y2[-1] \, .....;
#X text 248 136 the 'set' commands sets the initial previous values
;
#X obj 128 298 tabsend~ lorenz1;
#X obj 234 278 tabsend~ lorenz2;
#X obj 339 259 tabsend~ lorenz3;
#X obj 627 280 block~ 2048;
#X text 669 133 Lorenz Equations;
#X obj 128 185 fexpr~ $y1+pr * ($y2-$y1)*dt \; $y2 +(-$y1*$y3 + r*$y1-$y2)*dt
\; $y3+($y1*$y2 - b*$y3)*dt;
#X text 672 197 dZ/dt = -bZ;
#X text 669 167 dX/dt = pr * (X - Y);
#X text 668 147 written with 3 state variable X \, Y \, and Z;
#X text 670 182 dY/dt = -XZ + rX - y;
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#X restore 308 541 pd lorenz equations for visualization;
#X text 68 24 by Shahrokh Yadegari;