本文介绍了将签署的IEEE 754浮点数转换为十六进制表示形式的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧! 问题描述 29岁程序员,3月因学历无情被辞! 我正在使用Lua的一个前端,不幸的是这个前端已经过时,所以我在这里遇到了版本5.1,这意味着 bit32 库不可用我可能可以用它来转换)。 所以我想知道是否有人知道我可以实现一个浮点到二进制(数字)函数,或者更好,浮点到十六进制。到目前为止,我所能想到的最好的是十进制二进制/十六进制函数... 解决方案以下函数使用来自FrançoisPerrad的 lua-MessagePack 的一些代码。 pre $函数float2hex(n) if n == 0.0然后返回0.0结束 本地标志= 0 如果n sign = 0x80 n = -n end 本地mant,expo = math.frexp(n) local hext = {} 如果mant〜= mant然后 hext [#hext + 1] = string.char(0xFF,0x88,0x00,0x00) elseif mant ==数学.huge或expo> 0x80然后 if sign == 0 then hext [#hext + 1] = string.char(0x7F,0x80,0x00,0x00) else hext [#hext + 1] = string.char(0xFF,0x80,0x00,0x00) end $ b elseif(mant == 0.0 and expo == 0)or expo< -0x7E然后 hext [#hext + 1] = string.char(sign,0x00,0x00,0x00) else expo = expo + 0x7E mant =(mant * 2.0 - 1.0)* math.ldexp(0.5,24) hext [#hext + 1] = string.char(sign + math.floor(expo / 0x2),(expo %0x2)* 0x80 + math.floor(mant / 0x10000), math.floor(mant / 0x100)%0x100, mant%0x100) end 返回字符串(string.gsub(table.concat(hext),(。)),函数(c)返回string.format(%02X%s,string.byte(c), )end)16) end 函数hex2float(c) if c == 0然后返回0.0结束 local c = string。 gsub(string.format(%X,c),(..),函数(x)返回string.char(tonumber(x,16))end) local b1,b2,b3, b4 = string.byte(c,1,4) local sign = b1> (b2%0x80)* 0x100 + b3)* 0x100 + b4 本地expo =(b1%0x80)* 0x2 + if sign then sign = -1 else sign = 1 end local n if mant == 0 and expo == 0 then n = sign * 0.0 elseif expo == 0xFF then if mant == 0 then n = sign * math.huge else n = 0.0 / 0.0 end else n = sign * math.ldexp(1.0 + mant / 0x800000,expo - 0x7F) end return n end I'm using a front-end of Lua which is unfortunately outdated, so I'm stuck with version 5.1 here, meaning the bit32 library is out of reach (which I probably could have used to convert this).So I'm wondering if anyone knows of a way I could implement either a floating-point to binary (digits) function or, better yet, floating-point to hex. The best I've been able to come up with so far is a decimal to binary/hex function... 解决方案 The following functions uses some code from François Perrad's lua-MessagePack. A big thank you goes to him.function float2hex (n) if n == 0.0 then return 0.0 end local sign = 0 if n < 0.0 then sign = 0x80 n = -n end local mant, expo = math.frexp(n) local hext = {} if mant ~= mant then hext[#hext+1] = string.char(0xFF, 0x88, 0x00, 0x00) elseif mant == math.huge or expo > 0x80 then if sign == 0 then hext[#hext+1] = string.char(0x7F, 0x80, 0x00, 0x00) else hext[#hext+1] = string.char(0xFF, 0x80, 0x00, 0x00) end elseif (mant == 0.0 and expo == 0) or expo < -0x7E then hext[#hext+1] = string.char(sign, 0x00, 0x00, 0x00) else expo = expo + 0x7E mant = (mant * 2.0 - 1.0) * math.ldexp(0.5, 24) hext[#hext+1] = string.char(sign + math.floor(expo / 0x2), (expo % 0x2) * 0x80 + math.floor(mant / 0x10000), math.floor(mant / 0x100) % 0x100, mant % 0x100) end return tonumber(string.gsub(table.concat(hext),"(.)", function (c) return string.format("%02X%s",string.byte(c),"") end), 16)endfunction hex2float (c) if c == 0 then return 0.0 end local c = string.gsub(string.format("%X", c),"(..)",function (x) return string.char(tonumber(x, 16)) end) local b1,b2,b3,b4 = string.byte(c, 1, 4) local sign = b1 > 0x7F local expo = (b1 % 0x80) * 0x2 + math.floor(b2 / 0x80) local mant = ((b2 % 0x80) * 0x100 + b3) * 0x100 + b4 if sign then sign = -1 else sign = 1 end local n if mant == 0 and expo == 0 then n = sign * 0.0 elseif expo == 0xFF then if mant == 0 then n = sign * math.huge else n = 0.0/0.0 end else n = sign * math.ldexp(1.0 + mant / 0x800000, expo - 0x7F) end return nend 这篇关于将签署的IEEE 754浮点数转换为十六进制表示形式的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持! 上岸,阿里云!
06-16 18:11