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!!!Writing R Extensions(Version 2.7.1 (2008-06-23)):::6 R API: Cコードへのエントリーポイント
*投稿者： みゅ
*カテゴリ： なし
*優先度： 普通
*状態： 完了
*日時： 2010年01月10日 16時25分03秒
//{{bugstate}}
!!内容
*適当訳、参照は自己責任でお願いします・・・
!!!6 R API: Cコードへのエントリーポイント
!!6.1 メモリーの確保
!6.1.1 Transient storage allocation
!6.1.2 User-controlled memory
!!6.2 Error handling
!6.2.1 Error handling from FORTRAN
!!6.3 Random number generation
!!6.4 Missing and IEEE special values
!!6.5 Printing
!6.5.1 Printing from FORTRAN
!!6.6 Calling C from FORTRAN and vice versa
!!6.7 Numerical analysis subroutines
!6.7.1 Distribution functions
 double dnorm(double x, double mu, double sigma, int give_log);
 double pnorm(double x, double mu, double sigma, int lower_tail, int give_log);
 double qnorm(double p, double mu, double sigma, int lower_tail, int log_p);
 double rnorm(double mu, double sigma);
*For reference, the following table gives the basic name (to be prefixed by ‘d’, ‘p’, ‘q’ or ‘r’ apart from the exceptions noted) and distribution-specific arguments for the complete set of distributions.
 beta beta a, b
 non-central beta nbeta a, b, ncp
 binomial binom n, p
 Cauchy cauchy location, scale
 chi-squared chisq df
 non-central chi-squared nchisq df, ncp
 exponential exp scale (and not rate)
 F f n1, n2
 non-central F nf n1, n2, ncp
 gamma gamma shape, scale
 geometric geom p
 hypergeometric hyper NR, NB, n
 logistic logis location, scale
 lognormal lnorm logmean, logsd
 negative binomial nbinom size, prob
 normal norm mu, sigma
 Poisson pois lambda
 Student’s t t n
 non-central t nt df, delta
 Studentized range tukey (*) rr, cc, df
 uniform unif a, b
 Weibull weibull shape, scale
 Wilcoxon rank sum wilcox m, n
 Wilcoxon signed rank signrank n

!6.7.2 Mathematical functions
 double gammafn (double x) [Function]
 double lgammafn (double x) [Function]
 double digamma (double x) [Function]
 double trigamma (double x) [Function]
 double tetragamma (double x) [Function]
 double pentagamma (double x) [Function]
 double psigamma (double x, double deriv) [Function]
*The Gamma function, the natural logarithm of its absolute value and first four derivatives and the n-th derivative of Psi, the digamma function.
 double beta (double a, double b) [Function]
 double lbeta (double a, double b) [Function]
*The (complete) Beta function and its natural logarithm.
 double choose (double n, double k) [Function]
 double lchoose (double n, double k) [Function]
*The number of combinations of k items chosen from from n and its natural logarithm. k is rounded to the nearest integer (with a warning if needed).
 double bessel_i (double x, double nu, double expo) [Function]
 double bessel_j (double x, double nu) [Function]
 double bessel_k (double x, double nu, double expo) [Function]
 double bessel_y (double x, double nu) [Function]
*Bessel functions of types I, J, K and Y with index nu. For bessel_i and bessel_k there is the option to return exp(-x) I(x; nu) or exp(x) K(x; nu) if expo is 2. (Use expo == 1 for unscaled values.)

!6.7.3 Numerical Utilities
!6.7.4 Mathematical constants
!!6.8 Optimization
*optimが元となるCコードに直接アクセスすることができる．ユーザーは最小化したい関数を次の定義で与える必要がある．
 typedef double optimfn(int n, double *par, void *ex);
*１番目のパラメータは２番目のパラメータで与える変数の数である．The third argument is a pointer passed down from the calling routine, normally used to carry auxiliary information.
*いくつかの方法では以下の微係数も必要になる．
 typedef void optimgr(int n, double *par, double *gr, void *ex);
*これはgr引数を通じて（微係数が）返される．No function is provided for finite-differencing, nor for approximating the Hessian at the result.
*インターフェース(ヘッダーファイル‘R_ext/Applic.h’で定義されている)は
*Nelder Mead:
 void nmmin(int n, double *xin, double *x, double *Fmin, optimfn fn,
     int *fail, double abstol, double intol, void *ex,
     double alpha, double beta, double gamma, int trace,
     int *fncount, int maxit);
*BFGS:
 void vmmin(int n, double *x, double *Fmin,
     optimfn fn, optimgr gr, int maxit, int trace,
     int *mask, double abstol, double reltol, int nREPORT,
     void *ex, int *fncount, int *grcount, int *fail);
*Conjugate gradients:
 void cgmin(int n, double *xin, double *x, double *Fmin,
     optimfn fn, optimgr gr, int *fail, double abstol,
     double intol, void *ex, int type, int trace,
     int *fncount, int *grcount, int maxit);
*Limited-memory BFGS with bounds:
 void lbfgsb(int n, int lmm, double *x, double *lower,
     double *upper, int *nbd, double *Fmin, optimfn fn,
     optimgr gr, int *fail, void *ex, double factr,
     double pgtol, int *fncount, int *grcount,
     int maxit, char *msg, int trace, int nREPORT);
*Simulated annealing:
 void samin(int n, double *x, double *Fmin, optimfn fn, int maxit,
     int tmax, double temp, int trace, void *ex);
*多くの引数が複数のタイプの手法で共通である．ｎはパラメーター（訳者 注：changing variablesのこと）ｘの数である．xinはｘの初期値であり、ｘに最終結果がセットされて戻ってくる．また関数の最終の値がFminにセットされる．他のパラメーターの説明は関数「optim」のヘルプページで見つかるだろう．ｎｂｄの値についてはソースコード「src/appl/lbfgsb.c」を見よ．そこにはどのような境界が使われるかを特定している．

!!6.9 Integration
 typedef void integr_fn(double *x, int n, void *ex);
*There are interfaces (defined in header ‘R_ext/Applic.h’) for definite and for indefinite integrals. ‘Indefinite’ means that at least one of the integration boundaries is not finite.
*Finite:
 void Rdqags(integr_fn f, void *ex, double *a, double *b,
 double *epsabs, double *epsrel,
 double *result, double *abserr, int *neval, int *ier,
 int *limit, int *lenw, int *last,
 int *iwork, double *work);
*Indefinite:
 void Rdqagi(integr_fn f, void *ex, double *bound, int *inf,
 double *epsabs, double *epsrel,
 double *result, double *abserr, int *neval, int *ier,
 int *limit, int *lenw, int *last,
 int *iwork, double *work);

!!6.10 Utility functions
!!6.11 Re-encoding
!!6.12 Allowing interrupts
!!6.13 Platform and version information
!!6.14 Inlining C functions
!!6.15 Controlling visibility
!!6.16 Using these functions in your own C code
!!6.17 Organization of header files


!!コメント
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