怎么样在VC++6里面使用MPFR

fly

忘记问另外一个问题了。 MPFR与GMP有什么不同啊，看不懂英文。哪个更加快点？哪个更加容易使用啊？ 如果MPFR好用，希望有大牛教我一下怎么用MPFR。 唉，天天被密码搞得头晕啊。 matlab怎么不支持高精度整数啊，搞得我做密码实验还要跑到VC去，加完密还要再跑到matlab来，不知要怎么办！头快爆炸了。 PS：matlab要怎么样才读取GMP计算出来结果（全是大整数）啊？ 谢谢各位大牛了。

G-Spider

matlab 支持高精度整数。

fly

Are you sure? 我怎么找不到呢？ 要怎么样才能用啊？用哪个函数？

G-Spider

比如： >> vpa('(1+sqrt(5))/2',20) 相关参考： >> help vpa VPA Variable precision arithmetic. R = VPA(S) numerically evaluates each element of the double matrix S using variable precision floating point arithmetic with D decimal digit accuracy, where D is the current setting of DIGITS. The resulting R is a SYM. VPA(S,D) uses D digits, instead of the current setting of DIGITS. D is an integer or the SYM representation of a number. It is important to avoid the evaluation of an expression using double precision floating point arithmetic before it is passed to VPA. For example, phi = vpa((1+sqrt(5))/2) first computes a 16-digit approximation to the golden ratio, then converts that approximation to one with d digits, where d is the current setting of DIGITS. To get full precision, use unevaluated string or symbolic arguments, phi = vpa('(1+sqrt(5))/2') or s = sym('sqrt(5)') phi = vpa((1+s)/2); Additional examples: vpa(pi,780) shows six consecutive 9's near digit 770 in the decimal expansion of pi. vpa(hilb(2),5) returns [ 1., .50000] [.50000, .33333] See also double, digits.

fly

可是如果我是要编一个加密算法，涉及到几千比特的整数的模加，模乘时，还能用vpa吗？

G-Spider

2# G-Spider 准确地说，matlab7用gmp作为大数运算的内核。 向量、矩阵等运算用到atlas 、mkl、ipp、lapack等。 FFT用fftw3。 ...

wayne

可以试试这个工具箱： http://www.mathworks.com/matlabc ... -toolbox-for-matlab http://www.thedigitalmap.com/~carlos/software/index.htm