小编Jon*_*FTW的帖子

我做了一个名为的文件time.hs.它包含一个函数,用于测量另一个函数的执行时间.

有没有办法将time.hs文件导入另一个Haskell脚本？

我想要的东西:

module Main where
import C:\Haskell\time.hs

main = do
    putStrLn "Starting..."
    time $ print answer
    putStrLn "Done."

时间在'time.hs'中定义为:

module time where
Import <necessary modules>

time a = do
start <- getCPUTime
v <- a
end   <- getCPUTime
let diff = (fromIntegral (end - start)) / (10^12)
printf "Computation time: %0.3f sec\n" (diff :: Double)
return v

我不知道如何导入或加载单独的.hs文件.time.hs在导入之前是否需要将文件编译到模块中？

我在Haskell中有一个函数,它从列表中找到取幂的最大值:

prob99 = maximum $ map (\xs -> (head xs)^(head (tail xs))) numbers

我需要找到的是最终值在结果列表中的位置.我该怎么做？

编辑:我找到了一个像这样的解决方案:

n = [[519432,525806],[632382,518061]....
prob99b [a,b] = b* (log a)
answer = snd $ maximum (zip  (map prob99b n) [1..])

一个一直困扰我的快速问题.Haskell是否在返回布尔值的函数中执行所有等价测试,即使返回false值也是如此？

例如

f a b = ((a+b) == 2) && ((a*b) == 2)

如果第一个测试返回false,它会在第二个测试之后执行&&吗？或者哈斯克尔是否懒得不去做并继续前进？

我在我的应用程序中使用JTable并希望有2行标题,类似于:

这甚至是可能还是我必须做别的事？如果是这样,什么？使用Supertitle-titleA,SuperTitle-titleB将占用太多空间并使信息冗余.

我在eulerproject做了问题21.一部分需要找到一个数字的适当除数列表.即有剩余部分n和少数部分的数量n.所以我做了这个Haskell,但GHCI对我很生气.

divisors n =[ n | n <- [1..(n-1)], n `rem` [1..(n-1)] ==0 ]

问题是我不知道如何制作:

n `rem` [1..(n-1)]

所以它只返回小于n该分数的数字n.

我正在项目euler 做问题62,并提出以下测试数字是否为立方数:

isInt x = x == fromInteger (round x)
isCube x= isInt $ x**(1/3)

但由于浮点错误,它返回不正确的结果:

*Main> isCube (384^3)
False

有没有办法实现更可靠的立方体测试？

在旁注中,这是我的解决方案的其余部分,由于类型接口错误,它不起作用filter (isCube) (perms n):

cubes = [n^3|n<-[1..]]
perms n = map read $ permutations $ show n :: [Integer]
answer = head [n|n<-cubes,(length $ filter (isCube) (perms n)) == 5]

我需要做些什么来修复错误？

No instances for (Floating Integer, RealFrac Integer)
   arising from a use of `isCube' at prob62.hs:10:44-49

任何优化也是受欢迎的;-)

我有以下html和CSS.但我无法弄清楚的是如何在主div的右侧设置标签div.所以他们像书签一样伸出正确的位置.

.main {
    -moz-border-radius:10px;
    height: 75%;
    width: 60%;
    position: absolute;
    top: 15%;
    left: 20%;
    right: auto;
  }
.tabs {
    width: 50px;
    height: 1.3em;
    position: absolute;
    float: right;
}
 #tab { margin: 10px 10px 10px 0px;}

和HTML:

<div class="main">
    <div id="content">
       Some main content
    </div>
 </div>
 <div class="tabs">
     <div class="tabs" id="tab1">
         <a href="#" alt="Home">
             Home
         </a>
      </div>
      <div class="tabs" id="tab2">
          <a href="#" alt="About">
              About
          </a>
      </div>
</div>

好的,所以继续我之前的问题后,我最终得到了以下代码:

module Main where

import Data.List

chain n | n == 0       = error "What are you on about?"
        | n == 1       = [1]
        | rem n 2 == 0 = n : chain (n `div` 2) 
        | otherwise    = n : chain (3 * n + 1)


chainLength n =  (n,length (chain n))
array = map chainLength [1..999]
lengths = map chainLength [1..1000000]

compareSnd (_, y1) (_, y2) = compare y1 y2
longestChain = maximumBy compareSnd …

我试图让这个非常简单的脚本替换谷歌上的标题:

// ==UserScript==
// @name           Hell yeah
// @description    HELL YEAH
// @include        http://www.google.*
// ==/UserScript==
GM_addStyle("div #logo {background-image: url('http://img220.imageshack.us/img220/5676/1251559315224.jpg') !important}");

但是当我尝试使用它时没有任何反应.我究竟做错了什么？

获取以下错误,尝试从源代码编译TensorFlow.任何想法都会有所帮助.

bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasGemmEx@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasZhpmv_v2@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cufftExecD2Z@libcufft.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasSrotg_v2@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cufftExecR2C@libcufft.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasSsyrk_v2@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasDgemm_v2@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cufftSetWorkArea@libcufft.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasChemm_v2@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasZher2k_v2@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cufftExecC2C@libcufft.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `curandSetStream@libcurand.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `cublasDrotm_v2@libcublas.so.9.0'
bazel-out/host/bin/_solib_local/_U_S_Stensorflow_Spython_Cgen_Unn_Uops_Upy_Uwrappers_Ucc___Utensorflow/libtensorflow_framework.so: undefined reference to `curandSetPseudoRandomGeneratorSeed@libcurand.so.9.0'