diff --git a/CompileSteps/Makefile b/CompileSteps/Makefile
new file mode 100644
index 0000000..c23d4dc
--- /dev/null
+++ b/CompileSteps/Makefile
@@ -0,0 +1,10 @@
+
+%.E: %.c
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+
+%.o: %.c
+	$(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $<
+
+
+sm: sm.o simpleMath.o
+	$(CC) -o $@ simpleMath.o sm.o -lm
diff --git a/CompileSteps/simpleMath.E b/CompileSteps/simpleMath.E
new file mode 100644
index 0000000..881f32e
--- /dev/null
+++ b/CompileSteps/simpleMath.E
@@ -0,0 +1,449 @@
+# 1 "simpleMath.c"
+# 1 "<built-in>" 1
+# 1 "<built-in>" 3
+# 361 "<built-in>" 3
+# 1 "<command line>" 1
+# 1 "<built-in>" 2
+# 1 "simpleMath.c" 2
+# 1 "/usr/include/math.h" 1 3 4
+# 30 "/usr/include/math.h" 3 4
+# 1 "/usr/include/sys/cdefs.h" 1 3 4
+# 587 "/usr/include/sys/cdefs.h" 3 4
+# 1 "/usr/include/sys/_symbol_aliasing.h" 1 3 4
+# 588 "/usr/include/sys/cdefs.h" 2 3 4
+# 653 "/usr/include/sys/cdefs.h" 3 4
+# 1 "/usr/include/sys/_posix_availability.h" 1 3 4
+# 654 "/usr/include/sys/cdefs.h" 2 3 4
+# 31 "/usr/include/math.h" 2 3 4
+# 1 "/usr/include/Availability.h" 1 3 4
+# 206 "/usr/include/Availability.h" 3 4
+# 1 "/usr/include/AvailabilityInternal.h" 1 3 4
+# 207 "/usr/include/Availability.h" 2 3 4
+# 32 "/usr/include/math.h" 2 3 4
+# 44 "/usr/include/math.h" 3 4
+    typedef float float_t;
+    typedef double double_t;
+# 111 "/usr/include/math.h" 3 4
+extern int __math_errhandling(void);
+# 144 "/usr/include/math.h" 3 4
+extern int __fpclassifyf(float);
+extern int __fpclassifyd(double);
+extern int __fpclassifyl(long double);
+# 188 "/usr/include/math.h" 3 4
+inline __attribute__ ((__always_inline__)) int __inline_isfinitef(float);
+inline __attribute__ ((__always_inline__)) int __inline_isfinited(double);
+inline __attribute__ ((__always_inline__)) int __inline_isfinitel(long double);
+inline __attribute__ ((__always_inline__)) int __inline_isinff(float);
+inline __attribute__ ((__always_inline__)) int __inline_isinfd(double);
+inline __attribute__ ((__always_inline__)) int __inline_isinfl(long double);
+inline __attribute__ ((__always_inline__)) int __inline_isnanf(float);
+inline __attribute__ ((__always_inline__)) int __inline_isnand(double);
+inline __attribute__ ((__always_inline__)) int __inline_isnanl(long double);
+inline __attribute__ ((__always_inline__)) int __inline_isnormalf(float);
+inline __attribute__ ((__always_inline__)) int __inline_isnormald(double);
+inline __attribute__ ((__always_inline__)) int __inline_isnormall(long double);
+inline __attribute__ ((__always_inline__)) int __inline_signbitf(float);
+inline __attribute__ ((__always_inline__)) int __inline_signbitd(double);
+inline __attribute__ ((__always_inline__)) int __inline_signbitl(long double);
+
+inline __attribute__ ((__always_inline__)) int __inline_isfinitef(float __x) {
+    return __x == __x && __builtin_fabsf(__x) != __builtin_inff();
+}
+inline __attribute__ ((__always_inline__)) int __inline_isfinited(double __x) {
+    return __x == __x && __builtin_fabs(__x) != __builtin_inf();
+}
+inline __attribute__ ((__always_inline__)) int __inline_isfinitel(long double __x) {
+    return __x == __x && __builtin_fabsl(__x) != __builtin_infl();
+}
+inline __attribute__ ((__always_inline__)) int __inline_isinff(float __x) {
+    return __builtin_fabsf(__x) == __builtin_inff();
+}
+inline __attribute__ ((__always_inline__)) int __inline_isinfd(double __x) {
+    return __builtin_fabs(__x) == __builtin_inf();
+}
+inline __attribute__ ((__always_inline__)) int __inline_isinfl(long double __x) {
+    return __builtin_fabsl(__x) == __builtin_infl();
+}
+inline __attribute__ ((__always_inline__)) int __inline_isnanf(float __x) {
+    return __x != __x;
+}
+inline __attribute__ ((__always_inline__)) int __inline_isnand(double __x) {
+    return __x != __x;
+}
+inline __attribute__ ((__always_inline__)) int __inline_isnanl(long double __x) {
+    return __x != __x;
+}
+inline __attribute__ ((__always_inline__)) int __inline_signbitf(float __x) {
+    union { float __f; unsigned int __u; } __u;
+    __u.__f = __x;
+    return (int)(__u.__u >> 31);
+}
+inline __attribute__ ((__always_inline__)) int __inline_signbitd(double __x) {
+    union { double __f; unsigned long long __u; } __u;
+    __u.__f = __x;
+    return (int)(__u.__u >> 63);
+}
+
+inline __attribute__ ((__always_inline__)) int __inline_signbitl(long double __x) {
+    union {
+        long double __ld;
+        struct{ unsigned long long __m; unsigned short __sexp; } __p;
+    } __u;
+    __u.__ld = __x;
+    return (int)(__u.__p.__sexp >> 15);
+}
+
+
+
+
+
+
+
+inline __attribute__ ((__always_inline__)) int __inline_isnormalf(float __x) {
+    return __inline_isfinitef(__x) && __builtin_fabsf(__x) >= 1.17549435e-38F;
+}
+inline __attribute__ ((__always_inline__)) int __inline_isnormald(double __x) {
+    return __inline_isfinited(__x) && __builtin_fabs(__x) >= 2.2250738585072014e-308;
+}
+inline __attribute__ ((__always_inline__)) int __inline_isnormall(long double __x) {
+    return __inline_isfinitel(__x) && __builtin_fabsl(__x) >= 3.36210314311209350626e-4932L;
+}
+# 322 "/usr/include/math.h" 3 4
+extern float acosf(float);
+extern double acos(double);
+extern long double acosl(long double);
+
+extern float asinf(float);
+extern double asin(double);
+extern long double asinl(long double);
+
+extern float atanf(float);
+extern double atan(double);
+extern long double atanl(long double);
+
+extern float atan2f(float, float);
+extern double atan2(double, double);
+extern long double atan2l(long double, long double);
+
+extern float cosf(float);
+extern double cos(double);
+extern long double cosl(long double);
+
+extern float sinf(float);
+extern double sin(double);
+extern long double sinl(long double);
+
+extern float tanf(float);
+extern double tan(double);
+extern long double tanl(long double);
+
+extern float acoshf(float);
+extern double acosh(double);
+extern long double acoshl(long double);
+
+extern float asinhf(float);
+extern double asinh(double);
+extern long double asinhl(long double);
+
+extern float atanhf(float);
+extern double atanh(double);
+extern long double atanhl(long double);
+
+extern float coshf(float);
+extern double cosh(double);
+extern long double coshl(long double);
+
+extern float sinhf(float);
+extern double sinh(double);
+extern long double sinhl(long double);
+
+extern float tanhf(float);
+extern double tanh(double);
+extern long double tanhl(long double);
+
+extern float expf(float);
+extern double exp(double);
+extern long double expl(long double);
+
+extern float exp2f(float);
+extern double exp2(double);
+extern long double exp2l(long double);
+
+extern float expm1f(float);
+extern double expm1(double);
+extern long double expm1l(long double);
+
+extern float logf(float);
+extern double log(double);
+extern long double logl(long double);
+
+extern float log10f(float);
+extern double log10(double);
+extern long double log10l(long double);
+
+extern float log2f(float);
+extern double log2(double);
+extern long double log2l(long double);
+
+extern float log1pf(float);
+extern double log1p(double);
+extern long double log1pl(long double);
+
+extern float logbf(float);
+extern double logb(double);
+extern long double logbl(long double);
+
+extern float modff(float, float *);
+extern double modf(double, double *);
+extern long double modfl(long double, long double *);
+
+extern float ldexpf(float, int);
+extern double ldexp(double, int);
+extern long double ldexpl(long double, int);
+
+extern float frexpf(float, int *);
+extern double frexp(double, int *);
+extern long double frexpl(long double, int *);
+
+extern int ilogbf(float);
+extern int ilogb(double);
+extern int ilogbl(long double);
+
+extern float scalbnf(float, int);
+extern double scalbn(double, int);
+extern long double scalbnl(long double, int);
+
+extern float scalblnf(float, long int);
+extern double scalbln(double, long int);
+extern long double scalblnl(long double, long int);
+
+extern float fabsf(float);
+extern double fabs(double);
+extern long double fabsl(long double);
+
+extern float cbrtf(float);
+extern double cbrt(double);
+extern long double cbrtl(long double);
+
+extern float hypotf(float, float);
+extern double hypot(double, double);
+extern long double hypotl(long double, long double);
+
+extern float powf(float, float);
+extern double pow(double, double);
+extern long double powl(long double, long double);
+
+extern float sqrtf(float);
+extern double sqrt(double);
+extern long double sqrtl(long double);
+
+extern float erff(float);
+extern double erf(double);
+extern long double erfl(long double);
+
+extern float erfcf(float);
+extern double erfc(double);
+extern long double erfcl(long double);
+
+
+
+
+extern float lgammaf(float);
+extern double lgamma(double);
+extern long double lgammal(long double);
+
+extern float tgammaf(float);
+extern double tgamma(double);
+extern long double tgammal(long double);
+
+extern float ceilf(float);
+extern double ceil(double);
+extern long double ceill(long double);
+
+extern float floorf(float);
+extern double floor(double);
+extern long double floorl(long double);
+
+extern float nearbyintf(float);
+extern double nearbyint(double);
+extern long double nearbyintl(long double);
+
+extern float rintf(float);
+extern double rint(double);
+extern long double rintl(long double);
+
+extern long int lrintf(float);
+extern long int lrint(double);
+extern long int lrintl(long double);
+
+extern float roundf(float);
+extern double round(double);
+extern long double roundl(long double);
+
+extern long int lroundf(float);
+extern long int lround(double);
+extern long int lroundl(long double);
+
+
+
+
+extern long long int llrintf(float);
+extern long long int llrint(double);
+extern long long int llrintl(long double);
+
+extern long long int llroundf(float);
+extern long long int llround(double);
+extern long long int llroundl(long double);
+
+
+extern float truncf(float);
+extern double trunc(double);
+extern long double truncl(long double);
+
+extern float fmodf(float, float);
+extern double fmod(double, double);
+extern long double fmodl(long double, long double);
+
+extern float remainderf(float, float);
+extern double remainder(double, double);
+extern long double remainderl(long double, long double);
+
+extern float remquof(float, float, int *);
+extern double remquo(double, double, int *);
+extern long double remquol(long double, long double, int *);
+
+extern float copysignf(float, float);
+extern double copysign(double, double);
+extern long double copysignl(long double, long double);
+
+extern float nanf(const char *);
+extern double nan(const char *);
+extern long double nanl(const char *);
+
+extern float nextafterf(float, float);
+extern double nextafter(double, double);
+extern long double nextafterl(long double, long double);
+
+extern double nexttoward(double, long double);
+extern float nexttowardf(float, long double);
+extern long double nexttowardl(long double, long double);
+
+extern float fdimf(float, float);
+extern double fdim(double, double);
+extern long double fdiml(long double, long double);
+
+extern float fmaxf(float, float);
+extern double fmax(double, double);
+extern long double fmaxl(long double, long double);
+
+extern float fminf(float, float);
+extern double fmin(double, double);
+extern long double fminl(long double, long double);
+
+extern float fmaf(float, float, float);
+extern double fma(double, double, double);
+extern long double fmal(long double, long double, long double);
+# 565 "/usr/include/math.h" 3 4
+extern float __inff(void) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+extern double __inf(void) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+extern long double __infl(void) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+
+extern float __nan(void) __attribute__((availability(macosx,introduced=10.0)));
+# 597 "/usr/include/math.h" 3 4
+extern float __exp10f(float) __attribute__((availability(macosx,introduced=10.9)));
+extern double __exp10(double) __attribute__((availability(macosx,introduced=10.9)));
+
+
+
+
+
+inline __attribute__ ((__always_inline__)) void __sincosf(float __x, float *__sinp, float *__cosp);
+inline __attribute__ ((__always_inline__)) void __sincos(double __x, double *__sinp, double *__cosp);
+# 614 "/usr/include/math.h" 3 4
+extern float __cospif(float) __attribute__((availability(macosx,introduced=10.9)));
+extern double __cospi(double) __attribute__((availability(macosx,introduced=10.9)));
+extern float __sinpif(float) __attribute__((availability(macosx,introduced=10.9)));
+extern double __sinpi(double) __attribute__((availability(macosx,introduced=10.9)));
+extern float __tanpif(float) __attribute__((availability(macosx,introduced=10.9)));
+extern double __tanpi(double) __attribute__((availability(macosx,introduced=10.9)));
+# 645 "/usr/include/math.h" 3 4
+inline __attribute__ ((__always_inline__)) void __sincospif(float __x, float *__sinp, float *__cosp);
+inline __attribute__ ((__always_inline__)) void __sincospi(double __x, double *__sinp, double *__cosp);
+
+
+
+
+
+
+struct __float2 { float __sinval; float __cosval; };
+struct __double2 { double __sinval; double __cosval; };
+
+extern struct __float2 __sincosf_stret(float);
+extern struct __double2 __sincos_stret(double);
+extern struct __float2 __sincospif_stret(float);
+extern struct __double2 __sincospi_stret(double);
+
+inline __attribute__ ((__always_inline__)) void __sincosf(float __x, float *__sinp, float *__cosp) {
+    const struct __float2 __stret = __sincosf_stret(__x);
+    *__sinp = __stret.__sinval; *__cosp = __stret.__cosval;
+}
+
+inline __attribute__ ((__always_inline__)) void __sincos(double __x, double *__sinp, double *__cosp) {
+    const struct __double2 __stret = __sincos_stret(__x);
+    *__sinp = __stret.__sinval; *__cosp = __stret.__cosval;
+}
+
+inline __attribute__ ((__always_inline__)) void __sincospif(float __x, float *__sinp, float *__cosp) {
+    const struct __float2 __stret = __sincospif_stret(__x);
+    *__sinp = __stret.__sinval; *__cosp = __stret.__cosval;
+}
+
+inline __attribute__ ((__always_inline__)) void __sincospi(double __x, double *__sinp, double *__cosp) {
+    const struct __double2 __stret = __sincospi_stret(__x);
+    *__sinp = __stret.__sinval; *__cosp = __stret.__cosval;
+}
+
+
+
+
+
+
+
+extern double j0(double) __attribute__((availability(macosx,introduced=10.0)));
+extern double j1(double) __attribute__((availability(macosx,introduced=10.0)));
+extern double jn(int, double) __attribute__((availability(macosx,introduced=10.0)));
+extern double y0(double) __attribute__((availability(macosx,introduced=10.0)));
+extern double y1(double) __attribute__((availability(macosx,introduced=10.0)));
+extern double yn(int, double) __attribute__((availability(macosx,introduced=10.0)));
+extern double scalb(double, double);
+extern int signgam;
+# 751 "/usr/include/math.h" 3 4
+extern long int rinttol(double) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+
+extern long int roundtol(double) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+
+extern double drem(double, double) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+
+extern int finite(double) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+
+extern double gamma(double) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+
+extern double significand(double) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+
+
+struct exception {
+    int type;
+    char *name;
+    double arg1;
+    double arg2;
+    double retval;
+};
+
+extern int matherr(struct exception *) __attribute__((availability(macosx,introduced=10.0,deprecated=10.9)));
+# 2 "simpleMath.c" 2
+
+double
+sin2(double x)
+{
+    return( sin(2 * x) );
+}
diff --git a/CompileSteps/simpleMath.c b/CompileSteps/simpleMath.c
new file mode 100644
index 0000000..2be94fb
--- /dev/null
+++ b/CompileSteps/simpleMath.c
@@ -0,0 +1,9 @@
+#include <math.h>
+
+double
+sin2(double x)
+{
+    return( sin(2 * x) );
+}
+
+
diff --git a/CompileSteps/sm b/CompileSteps/sm
new file mode 100755
index 0000000..169ba3b
Binary files /dev/null and b/CompileSteps/sm differ
diff --git a/CompileSteps/sm.c b/CompileSteps/sm.c
new file mode 100644
index 0000000..3161cc6
--- /dev/null
+++ b/CompileSteps/sm.c
@@ -0,0 +1,20 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+extern double sin2(double);
+
+int
+main(int argc, char *argv[])
+{
+    double ans, value;
+
+    // check we have more than one command line argument, the first being the name of the program sm
+    if(argc < 2)
+	return(1);
+    // so we have two or more
+    value = atof(argv[1]);
+    
+    ans = sin2(value);
+    printf("%lf\n", ans);
+    return(0);
+}
diff --git a/Topics.md b/Topics.md
new file mode 100644
index 0000000..7d99225
--- /dev/null
+++ b/Topics.md
@@ -0,0 +1,40 @@
+
++ Calling existing C routine from 3rd party library
+   + simple routine that takes a vector of doubles and the length and 
+   + matrices and accessing the (i,j) element.
+ + Compiling 
+    + See CompileSteps
+    + pre-processor
+	   + include -I, 
+	+ Makevars
+	+ Compile
+	+ Link - executable or dynamic library
+	   + What is a shared library
+	   + Motivation
+	   + Benefits - hot-swappable
+	   + Drawbacks - finding it at run-time
+	   + security limitatins
+	      + LD_LIBRARY_PATH/DYLD_LIBRARY_PATH
+	+ Load
+ + wrapper routine
+ + return the result.	
+ + Debugging
+    + R -d gdb
++ Difference between .C() and .Call()
++ R API
+  + Protecting objects
++ Rcpp
++ Doing more in the routine to avoid returning an intermediate object.
+   + The externalptr type
+   + Releasing memory when eventually no longer used.
+   + Making certain not to use it when it has been freed.
+
+
+
+
+# Installing Software Locally
+
+# Configuration
+## CMake
+## Autoconf
+## Make
diff --git a/URLs b/URLs
new file mode 100644
index 0000000..df31b98
--- /dev/null
+++ b/URLs
@@ -0,0 +1,8 @@
+https://github.com/dertuxmalwieder/libvldmail
+
+http://libsound.io/
+
+
+
+GDB tricks
+https://blogs.oracle.com/linux/8-gdb-tricks-you-should-know-v2
\ No newline at end of file
diff --git a/dotC/src/dotC.c b/dotC/src/dotC.c
new file mode 100644
index 0000000..e01303a
--- /dev/null
+++ b/dotC/src/dotC.c
@@ -0,0 +1,7 @@
+
+void
+add1(double *x, int *len, double *ans)
+{
+    for(int i = 0; i < *len; i++) 
+	ans[i] = x[i] + 1;
+}
diff --git a/dotC/tests/show.R b/dotC/tests/show.R
new file mode 100644
index 0000000..40aa62b
--- /dev/null
+++ b/dotC/tests/show.R
@@ -0,0 +1,4 @@
+dyn.load("dotC.so")
+z = as.numeric(1:100)
+o = .C("add1", z, length(z), ans = numeric(length(z))) $ans
+o
diff --git a/getrusage/R/rusage.R b/getrusage/R/rusage.R
new file mode 100644
index 0000000..4be443b
--- /dev/null
+++ b/getrusage/R/rusage.R
@@ -0,0 +1,16 @@
+rusage =
+function(who = 0L)
+{
+    ans = .Call("R_getrusage", as.integer(who))
+    names(ans) = c("maxrss", "ixrss", "idrss", "isrss", "minflt", "majflt", "nswap", "inblock", "oublock", "msgsnd", "msgrcv", "nsignals", "nvcsw", "nivcsw")
+    ans
+}
+
+
+rusage2 =
+function(who = 0L)
+{
+    ans = .Call("R_getrusage2", as.integer(who))
+    names(ans) = c("utime", "stime", "maxrss", "ixrss", "idrss", "isrss", "minflt", "majflt", "nswap", "inblock", "oublock", "msgsnd", "msgrcv", "nsignals", "nvcsw", "nivcsw")
+    ans
+}