我正在尝试将自相关的不同组件打印在不同的行上:
import Data.Vector as V
import Statistics.Autocorrelation
import Data.Typeable
sampleA = [1.0, 2.0, 3.0, 4.0, 1.0, 2.0, 3.0, 4]
main = do
let res = autocorrelation $ V.fromList sampleA
putStr "Type of result of autocorrelation test: "
print $ typeOf res
print res
-- Prelude.mapM_ print res -- not working;
输出为:
Type of result of autocorrelation test: ((Vector Double),(Vector Double),(Vector Double))
([1.0,2.5e-2,-0.45,-0.325,0.5,0.125,-0.15],[1.0,-1.3255000000000001,-1.4039375473415425,-1.442999810318651,-1.5311377955236107,-1.5364636906417393,-1.544097864842309],[1.0,1.0755000000000001,1.1539375473415425,1.192999810318651,1.2811377955236107,1.2864636906417393,1.294097864842309])
然而,如果我取消最后一行的注释,就会出现错误:
• No instance for (Foldable ((,,) (Vector Double) (Vector Double)))
arising from a use of ‘Prelude.mapM_’
• In a stmt of a 'do' block: Prelude.mapM_ print res
In the expression:
do { let res = autocorrelation $ fromList sampleA;
putStr "Type of result of autocorrelation test: ";
print $ typeOf res;
print res;
.... }
In an equation for ‘main’:
main
= do { let res = ...;
putStr "Type of result of autocorrelation test: ";
print $ typeOf res;
.... }
如何将结果的所有部分打印在单独的行上?谢谢您的帮助。
case autocorrelation (V.fromList sampleA) of (a,b,c) -> mapM_ print [a,b,c]
,因为a、b、c
恰好是相同类型的Vector Double
。 - Will Ness