add inlet and arg for base, update docs

pd/doc/5.reference/log-help.pd

-#N canvas 428 60 555 619 10;
+#N canvas 626 70 555 619 10;
 #X obj 0 595 cnv 15 552 21 empty \$0-pddp.cnv.footer empty 20 12 0
 14 -228856 -66577 0;
 #X obj 0 0 cnv 15 552 40 empty \$0-pddp.cnv.header log 3 12 0 18 -204280
 -1 0;
-#X obj 0 389 cnv 3 550 3 empty \$0-pddp.cnv.inlets inlets 8 12 0 13
+#X obj 0 299 cnv 3 550 3 empty \$0-pddp.cnv.inlets inlets 8 12 0 13
 -228856 -1 0;
 #N canvas 483 285 494 344 META 0;
 #X text 12 105 LIBRARY internal;
@@ -21,13 +21,12 @@ for Pd version 0.42.;
 #X text 12 85 OUTLET_0 float;
 #X text 12 165 RELEASE_DATE 1997;
 #X restore 500 597 pd META;
-#X obj 0 454 cnv 3 550 3 empty \$0-pddp.cnv.outlets outlets 8 12 0
+#X obj 0 414 cnv 3 550 3 empty \$0-pddp.cnv.outlets outlets 8 12 0
 13 -228856 -1 0;
-#X obj 0 491 cnv 3 550 3 empty \$0-pddp.cnv.argument arguments 8 12
+#X obj 0 451 cnv 3 550 3 empty \$0-pddp.cnv.argument arguments 8 12
 0 13 -228856 -1 0;
 #X obj 0 518 cnv 3 550 3 empty \$0-pddp.cnv.more_info more_info 8 12
 0 13 -228856 -1 0;
-#X text 98 495 (none);
 #N canvas 215 516 428 109 Related_objects 0;
 #X obj 1 1 cnv 15 425 20 empty \$0-pddp.cnv.subheading empty 3 12 0
 14 -204280 -1 0;
@@ -45,22 +44,22 @@ for Pd version 0.42.;
 #X text 7 1 [log] Related Objects;
 #X obj 181 42 exp;
 #X restore 101 597 pd Related_objects;
-#X obj 78 398 cnv 17 3 45 empty \$0-pddp.cnv.let.0 0 5 9 0 16 -228856
+#X obj 78 308 cnv 17 3 45 empty \$0-pddp.cnv.let.0 0 5 9 0 16 -228856
 -162280 0;
-#X text 98 397 float;
-#X text 98 417 list;
-#X text 98 462 float;
-#X obj 78 463 cnv 17 3 17 empty \$0-pddp.cnv.let.0 0 5 9 0 16 -228856
+#X text 98 307 float;
+#X text 98 327 list;
+#X text 98 422 float;
+#X obj 78 423 cnv 17 3 17 empty \$0-pddp.cnv.let.0 0 5 9 0 16 -228856
 -162280 0;
-#X floatatom 239 217 0 0 0 0 - - -;
-#X floatatom 239 160 0 0 0 0 - - -;
-#X text 94 274 [log] will output the natural logarithm (base E) of
+#X floatatom 239 177 0 0 0 0 - - -;
+#X floatatom 239 120 0 0 0 0 - - -;
+#X text 94 234 [log] will output the natural logarithm (base E) of
 a number. The value of zero will produce "-1000" which represents "negative
 infinity".;
-#X obj 239 190 log;
+#X obj 239 150 log;
 #X obj 515 9 log;
 #X text 11 23 natural logarithm of a number;
-#X text 168 417 - a list will be truncated \, and the first element
+#X text 168 307 - a list will be truncated \, and the first element
 will be used as input.;
 #X obj 4 597 pddp/pddplink all_about_help_patches.pd -text Usage Guide
 ;
@@ -70,5 +69,18 @@ will be used as input.;
 #X obj 98 548 pddp/pddplink otherbinops-help.pd;
 #X obj 98 568 pddp/pddplink math-help.pd;
 #X text 217 568 - higher math objects;
-#X connect 15 0 17 0;
-#X connect 17 0 14 0;
+#X floatatom 282 118 5 0 0 1 base_value - -, f 5;
+#X obj 33 148 log 2;
+#X floatatom 33 173 5 0 0 0 - - -, f 5;
+#X floatatom 33 120 5 0 0 0 - - -, f 5;
+#X obj 78 358 cnv 17 3 30 empty \$0-pddp.cnv.let.0 1 5 9 0 16 -228856
+-162280 0;
+#X text 98 357 float;
+#X text 168 357 - set the base;
+#X text 78 485 1) float;
+#X text 138 485 - set the base;
+#X connect 14 0 16 0;
+#X connect 16 0 13 0;
+#X connect 27 0 16 1;
+#X connect 28 0 29 0;
+#X connect 30 0 28 0;

pd/src/x_arithmetic.c

@@ -636,19 +636,28 @@ static void sqrt_float(t_object *x, t_float f)
     outlet_float(x->ob_outlet, r);
 }
 
-static t_class *log_class;      /* ----------- log --------------- */
+static t_class *binop1_log_class;      /* ----------- log --------------- */
 
-static void *log_new(void)
+static void *binop1_log_new(t_floatarg f)
 {
-    t_object *x = (t_object *)pd_new(log_class);
-    outlet_new(x, &s_float);
-    return (x);
+    return (binop1_new(binop1_log_class, f));
 }
 
-static void log_float(t_object *x, t_float f)
+static void binop1_log_bang(t_binop *x)
 {
-    t_float r = (f > 0 ? LOG(f) : -1000);
-    outlet_float(x->ob_outlet, r);
+    t_float r;
+    if (x->x_f1 <= 0)
+        r = -1000;
+    else if (x->x_f2 <= 0)
+        r = LOG(x->x_f1);
+    else r = LOG(x->x_f1)/LOG(x->x_f2);
+        outlet_float(x->x_obj.ob_outlet, r);
+}
+
+static void binop1_log_float(t_binop *x, t_float f)
+{
+    x->x_f1 = f;
+    binop1_log_bang(x);
 }
 
 static t_class *exp_class;      /* ----------- exp --------------- */
@@ -791,6 +800,11 @@ void x_arithmetic_setup(void)
     class_addbang(binop1_min_class, binop1_min_bang);
     class_addfloat(binop1_min_class, (t_method)binop1_min_float);
 
+    binop1_log_class = class_new(gensym("log"), (t_newmethod)binop1_log_new,
+        0, sizeof(t_binop), 0, A_DEFFLOAT, 0);
+    class_addbang(binop1_log_class, binop1_log_bang);
+    class_addfloat(binop1_log_class, (t_method)binop1_log_float);    
+
         /* ------------------ binop2 ----------------------- */
 
     binop2_ee_class = class_new(gensym("=="), (t_newmethod)binop2_ee_new, 0,
@@ -911,10 +925,6 @@ void x_arithmetic_setup(void)
         sizeof(t_object), 0, 0);
     class_addfloat(sqrt_class, (t_method)sqrt_float);
 
-    log_class = class_new(gensym("log"), log_new, 0,
-        sizeof(t_object), 0, 0);
-    class_addfloat(log_class, (t_method)log_float);    
-
     exp_class = class_new(gensym("exp"), exp_new, 0,
         sizeof(t_object), 0, 0);
     class_addfloat(exp_class, (t_method)exp_float);