/*  -*- MaTX -*-
 *
 *  y–ผ‘Oz
 *      norm() - ƒmƒ‹ƒ€
 *
 *  yŒ`Žฎz
 *      x = norm(A)
 *         Real x;
 *         (Matrix|Array) A;
 *
 *      x = norm(A,k)
 *         Real x;
 *         (Matrix|Array) A;
 *         Integer k;
 *
 *  y‹@”\เ–พz
 *      norm(A)‚อCs—๑ A ‚ฬล‘ๅ“มˆู’l‚๐‹‚฿‚้Bnorm(A,1) ‚อCA ‚ฬ
 *      1-ƒmƒ‹ƒ€(—๑–ˆ‚ฬ˜a‚ฬล‘ๅ’l)‚๐‹‚฿‚้Bnorm(A,2)‚อCnorm(A)‚ฦ
 *      “™‚ต‚ขB
 *
 *  y—แ‘่z
 *      >> x = norm([[1 2 3][4 5 6]])
 *      x = 9.50803
 *      >> x = norm([[1 2 3][4 5 6]],1)
 *      x = 9
 *      >> x = norm([[1 2 3][4 5 6]],2)
 *      x = 9.50803
 *
 *  yŠึ˜A€–ฺz
 *      frobnorm(), infnorm()
 */