Haskell Hamming Sequence Logic
up vote
0
down vote
favorite
It was suggested I place this code here. I had posted it on StackOverflow for kind of review.
I found in Excel that a candidate number when evenly divided by one of [2,3,5] in can be found in previously generated hamming numbers. The problem is, I thought this would be a little faster. It seems terribly slow. It is, first-of-all correct.
The function takes two parameters, a seed list of Hamming numbers less than 10 and a candidate list of any size. I prefer to us a list of [2,3,5] multiples I call base
base = scanl (b a -> a+b) 2 $ cycle [1,1,1,1,2,1,1,2,2,1,1,2,2,1,1,2,1,1,1,1,2,2]
hamx ls (x:xs)
| even x && elem (div x 2) ls = hamx (x:ls) xs
| mod x 3 == 0 && elem (div x 3) ls = hamx (x:ls) xs
| mod x 5 == 0 && elem (div x 5) ls = hamx (x:ls) xs
| null xs = ls
| otherwise = hamx ls xs
I tried filter and any and others in place of elem. The list generates in reverse. The elem finds Hamming matches faster from the bottom and new Hamming numbers appear also at the bottom. So, the bottom is the top.
haskell
asked 14 mins ago
fp_mora
1012
add a comment |
up vote
0
down vote
favorite
It was suggested I place this code here. I had posted it on StackOverflow for kind of review.
I found in Excel that a candidate number when evenly divided by one of [2,3,5] in can be found in previously generated hamming numbers. The problem is, I thought this would be a little faster. It seems terribly slow. It is, first-of-all correct.
The function takes two parameters, a seed list of Hamming numbers less than 10 and a candidate list of any size. I prefer to us a list of [2,3,5] multiples I call base
base = scanl (b a -> a+b) 2 $ cycle [1,1,1,1,2,1,1,2,2,1,1,2,2,1,1,2,1,1,1,1,2,2]
hamx ls (x:xs)
| even x && elem (div x 2) ls = hamx (x:ls) xs
| mod x 3 == 0 && elem (div x 3) ls = hamx (x:ls) xs
| mod x 5 == 0 && elem (div x 5) ls = hamx (x:ls) xs
| null xs = ls
| otherwise = hamx ls xs
I tried filter and any and others in place of elem. The list generates in reverse. The elem finds Hamming matches faster from the bottom and new Hamming numbers appear also at the bottom. So, the bottom is the top.
haskell
asked 14 mins ago
fp_mora
1012
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
It was suggested I place this code here. I had posted it on StackOverflow for kind of review.
I found in Excel that a candidate number when evenly divided by one of [2,3,5] in can be found in previously generated hamming numbers. The problem is, I thought this would be a little faster. It seems terribly slow. It is, first-of-all correct.
The function takes two parameters, a seed list of Hamming numbers less than 10 and a candidate list of any size. I prefer to us a list of [2,3,5] multiples I call base
base = scanl (b a -> a+b) 2 $ cycle [1,1,1,1,2,1,1,2,2,1,1,2,2,1,1,2,1,1,1,1,2,2]
hamx ls (x:xs)
| even x && elem (div x 2) ls = hamx (x:ls) xs
| mod x 3 == 0 && elem (div x 3) ls = hamx (x:ls) xs
| mod x 5 == 0 && elem (div x 5) ls = hamx (x:ls) xs
| null xs = ls
| otherwise = hamx ls xs
I tried filter and any and others in place of elem. The list generates in reverse. The elem finds Hamming matches faster from the bottom and new Hamming numbers appear also at the bottom. So, the bottom is the top.
haskell
asked 14 mins ago
fp_mora
1012
It was suggested I place this code here. I had posted it on StackOverflow for kind of review.
I found in Excel that a candidate number when evenly divided by one of [2,3,5] in can be found in previously generated hamming numbers. The problem is, I thought this would be a little faster. It seems terribly slow. It is, first-of-all correct.
The function takes two parameters, a seed list of Hamming numbers less than 10 and a candidate list of any size. I prefer to us a list of [2,3,5] multiples I call base
base = scanl (b a -> a+b) 2 $ cycle [1,1,1,1,2,1,1,2,2,1,1,2,2,1,1,2,1,1,1,1,2,2]
hamx ls (x:xs)
| even x && elem (div x 2) ls = hamx (x:ls) xs
| mod x 3 == 0 && elem (div x 3) ls = hamx (x:ls) xs
| mod x 5 == 0 && elem (div x 5) ls = hamx (x:ls) xs
| null xs = ls
| otherwise = hamx ls xs
I tried filter and any and others in place of elem. The list generates in reverse. The elem finds Hamming matches faster from the bottom and new Hamming numbers appear also at the bottom. So, the bottom is the top.
haskell
haskell
asked 14 mins ago
fp_mora
1012
asked 14 mins ago
fp_mora
1012
asked 14 mins ago
fp_mora
1012
asked 14 mins ago
fp_mora
1012
asked 14 mins ago
fp_mora
1012
1012
add a comment |
add a comment |
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "196"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f209794%2fhaskell-hamming-sequence-logic%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Code Review Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f209794%2fhaskell-hamming-sequence-logic%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
