Compare one value to 100 element array?
Alert("comp1 ", ArrayCompare(tickarray0, tickarray, 0, 1, WHOLE_ARRAY)); Alert("comp2 ", ArrayCompare(tickarray0, tickarray, 0, 2, WHOLE_ARRAY)); Alert("comp3 ", ArrayCompare(tickarray0, tickarray, 0, 3, WHOLE_ARRAY)); Alert("comp4 ", ArrayCompare(tickarray0, tickarray, 0, 4, WHOLE_ARRAY)); Alert("comp5 ", ArrayCompare(tickarray0, tickarray, 0, 5, WHOLE_ARRAY)); Alert("comp6 ", ArrayCompare(tickarray0, tickarray, 0, 6, WHOLE_ARRAY)); Alert("comp7 ", ArrayCompare(tickarray0, tickarray, 0, 7, WHOLE_ARRAY)); Alert("comp8 ", ArrayCompare(tickarray0, tickarray, 0, 8, WHOLE_ARRAY)); Alert("comp9 ", ArrayCompare(tickarray0, tickarray, 0, 9, WHOLE_ARRAY));The only way?
What about a binary search in a sorted array?
nadiawicket: ArrayCompare() just compares a single element to a single element in the second array to be compared. I thought WHOLE_ARRAY was what I was looking for. Any clues? Make a 100 element array with all values same as x sounds clunky.
Is there a way to compare for example x to every value of array[] , when array has 100 elements?
Is there a way to compare for example x to every value of array[] , when array has 100 elements?
Alert("comp8 ", ArrayCompare(tickarray0, tickarray, 0, 8, WHOLE_ARRAY));
How to do this without going one by one? or do we have to go one by one?- That function compares two arrays. Makes no sense when you have one value. You want to search the array.
- If the array isn't ordered, yes you have to. It's not hard!
#define INDEX uint // Zero based /** Linear search an _array_ for a specific _value_. @returns INDEX * of the first element found with _value_ or _end_ if not found. */ template<typename Ti1, typename Ti2> static INDEX find(const Ti1& inp[], INDEX iBeg, INDEX iEnd, const Ti2& value){ while(iBeg != iEnd && !(inp[iBeg] == value) ) ++iBeg; return iBeg; } /** Linear search an _array_ for a specific _value_, i.e.\ where the supplied * _pred_ `class` or `struct` method `is_member(T)` returns true. * @returns INDEX of the first element found or _end_ if not found. */ template<typename Ti, typename UnaryPredicate> static INDEX find_if(const Ti& inp[], INDEX iBeg, INDEX iEnd, UnaryPredicate& pred){ while(iBeg != iEnd && !pred.is_member(inp[iBeg] )) ++iBeg; return iBeg; }
- If the array is sorted, you can use a binary search. See Sort multiple arrays - MQL4 and MetaTrader 4 - MQL4 programming
forum
/** Returns the index in a __sorted__ _array_, the first element greater * than or equal to _value_. If all values are less than _value_, returns * _end_. */ template<typename Ti1, typename Ti2> INDEX lower_bound(const Ti1& inp[], INDEX iBeg, INDEX iEnd, const Ti2& value){ COUNT len = iEnd - iBeg; while(len > 0){ COUNT half = len >> 1; INDEX middle = iBeg + half; if(inp[middle] < value){ iBeg = middle + 1; len = len - half - 1; } else len = half; } return iBeg; } /** Returns the index in a __sorted__ _array_, the first element which does * not compare smaller than _value_ using the supplied _pred_ `class` or * `struct` method `is_before(T, T)` which creates a [strict weak * ordering](http://simple.wikipedia.org/wiki/Strict_weak_ordering "Strict * weak ordering - Simple English Wikipedia, the free encyclopedia"). If no * value is larger, returns _end_. */ template<typename Ti1, typename Ti2, typename BinaryPredicate> INDEX lower_bound(const Ti1& inp[], INDEX iBeg, INDEX iEnd, const Ti2& value, BinaryPredicate& pred){ COUNT len = iEnd - iBeg; while(len > 0){ COUNT half = len >> 1; INDEX middle = iBeg + half; if(pred.is_before(inp[middle], value) ){ iBeg = middle + 1; len = len - half - 1; } else len = half; } return iBeg; }
- or use a tree, not an array
Carl Schreiber:
What about a binary search in a sorted array?
What about a binary search in a sorted array?
Problem is the
ArrayBsearch() only returns closest value to what you are searching. I need it to return a plain yes or no. Looks like I'll have to use the manual one by one method for a 500 part array. The other suggestions are a little bit out of my league at the moment lets see how it goes.
#define INDEX uint // Zero based /** Linear search an _array_ for a specific _value_. @returns INDEX * of the first element found with _value_ or _end_ if not found. */ template<typename Ti1, typename Ti2> static INDEX find(const Ti1& inp[], INDEX iBeg, INDEX iEnd, const Ti2& value){ while(iBeg != iEnd && !(inp[iBeg] == value) ) ++iBeg; return iBeg; } /** Linear search an _array_ for a specific _value_, i.e.\ where the supplied * _pred_ `class` or `struct` method `is_member(T)` returns true. * @returns INDEX of the first element found or _end_ if not found. */ template<typename Ti, typename UnaryPredicate> static INDEX find_if(const Ti& inp[], INDEX iBeg, INDEX iEnd, UnaryPredicate& pred){ while(iBeg != iEnd && !pred.is_member(inp[iBeg] )) ++iBeg; return iBeg; }looks like it lemme see how i figure all of this out
whroeder1:
Thanks
- That function compares two arrays. Makes no sense when you have one value. You want to search the array.
- If the array isn't ordered, yes you have to. It's not hard!
- If the array is sorted, you can use a binary search. See Sort multiple arrays - MQL4 and MetaTrader 4 - MQL4 programming
forum
- or use a tree, not an array
whroeder1:
- That function compares two arrays. Makes no sense when you have one value. You want to search the array.
- If the array isn't ordered, yes you have to. It's not hard!
- If the array is sorted, you can use a binary search. See Sort multiple arrays - MQL4 and MetaTrader 4 - MQL4 programming
forum
- or use a tree, not an array
If you would explain a little, it would help a lot because the official documentation I didn't understand and its been like 10 hours. I'm stuck at how to actually enable/use templates, the official examples I just cant figure out.
#define INDEX uint // Zero based /** Linear search an _array_ for a specific _value_. @returns INDEX * of the first element found with _value_ or _end_ if not found. */ template<typename Ti1, typename Ti2> static INDEX find(const Ti1& inp[], INDEX iBeg, INDEX iEnd, const Ti2& value){ while(iBeg != iEnd && !(inp[iBeg] == value) ) ++iBeg; return iBeg;
#define INDEX uint // Zero based
Previous item; I just leave that as is and placed it on the top of file.
template<typename Ti1, typename Ti2>
Previous item; I substitutue ti1 and ti2 for the actual values?
static INDEX You are pulling this one here instead of at the top of the file again like #Define. I just put the array[] index here?
nadiawicket:
ArrayBsearch() only returns closest value to what you are searching. I need it to return a plain yes or no. Looks like I'll have to use the manual one by one method for a 500 part array. The other suggestions are a little bit out of my league at the moment lets see how it goes.
Problem is the
ArrayBsearch() only returns closest value to what you are searching. I need it to return a plain yes or no. Looks like I'll have to use the manual one by one method for a 500 part array. The other suggestions are a little bit out of my league at the moment lets see how it goes.
template<typename T1,typename T2> bool ArrayFind(const T1 &array[],const T2 value,int begin=0,int count=WHOLE_ARRAY) { int size=ArraySize(array); if(count==WHOLE_ARRAY) count=size-begin; if(begin+count>size) return(false); for(int i=begin;i<begin+count;i++) if(array[i]==value) return(true); return(false); }
Ernst Van Der Merwe:
If this works, you saved me like a week.template<typename T1,typename T2> bool ArrayFind(const T1 &array[],const T2 value,uint begin=0,uint count=WHOLE_ARRAY) { int size=ArraySize(array); if(count==WHOLE_ARRAY) count=size-begin; if(begin+count>size) return(false); for(int i=begin;i<count;i++) if(array[i]==value) return(true); return(false); }so
template<typename T1,typename T2>Previous item is where I put the Ti for the value of the first thing I want to compare? And t2 for the second parameter?
nadiawicket:
If this works, you saved me like a week.so
If this works, you saved me like a week.so
Previous item is where I put the Ti for the value of the first thing I want to compare? And t2 for the second parameter?
T1 is where the array is passed to and T2 is the value to be found.
double array1[]={1.2341,1.4789,1.6434,1.9487}; double value1=1.6434; if(ArrayFind(array1,value1)) Print("Value found!"); int array2[]={31,76,94,27,438,5}; double value2=5; if(ArrayFind(array2,value2,2,WHOLE_ARRAY)) Print("Value found!");
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How to do this without going one by one? Is there a way to compare for example
x to every value of array[] , when array has 100 elements?
or do we have to go one by one?
ArrayCompare() just compares a single element to a single element in the second array to be compared. I thought WHOLE_ARRAY was what I was looking for.
Any clues? Make a 100 element array with all values same as x sounds clunky