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 4 edited tags | link edited Mar 1 at 9:20 J. M. will be back soon♦ 100k1010 gold badges317317 silver badges476476 bronze badges Tweeted twitter.com/StackMma/status/1101089761228476417 occurred Feb 28 at 12:00 3 added 15 characters in body edited Feb 28 at 5:17 Roman 15.9k11 gold badge2121 silver badges5454 bronze badges I have two arrays, say array1 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; array2 = {13, 4, 6, 20, 21};  I want to compare these two arrays by cycling array1array1 through all elements in array2array2. The output should be the position in each array where they match a condition, where the condition array2 = array1[n]-1array2[[m]] = array1[[n]]-1 is true. That is, the output should be: output = {6,2}  Because in array2array2, 5-1 = 4$$5-1 = 4$$. (array1[6] = 5array1[[6]] = 5 and array2[2] = 4array2[[2]] = 4). So far, my code is output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ (I have no idea)  Where the code on the left hand side of Map gives me the positions of a true condition. On the right hand side of Map, I'm not sure what to do. To clarify a little bit, the code I want is similar to output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ Intersection[array1, array2]  Except I want the position of the element when array2 = array1-1array2 = array1-1 instead of when array1=array2array1 = array2. I have two arrays, say array1 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; array2 = {13, 4, 6, 20, 21};  I want to compare these two arrays by cycling array1 through all elements in array2. The output should be the position in each array where they match a condition, where the condition array2 = array1[n]-1 is true. That is, the output should be: output = {6,2}  Because in array2, 5-1 = 4. (array1[6] = 5 and array2[2] = 4). So far, my code is output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ (I have no idea)  Where the code on the left hand side of Map gives me the positions of a true condition. On the right hand side of Map, I'm not sure what to do. To clarify a little bit, the code I want is similar to output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ Intersection[array1, array2]  Except I want the position of the element when array2 = array1-1 instead of when array1=array2 I have two arrays, say array1 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; array2 = {13, 4, 6, 20, 21};  I want to compare these two arrays by cycling array1 through all elements in array2. The output should be the position in each array where they match a condition, where the condition array2[[m]] = array1[[n]]-1 is true. That is, the output should be: output = {6,2}  Because in array2, $$5-1 = 4$$. (array1[[6]] = 5 and array2[[2]] = 4). So far, my code is output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ (I have no idea)  Where the code on the left hand side of Map gives me the positions of a true condition. On the right hand side of Map, I'm not sure what to do. To clarify a little bit, the code I want is similar to output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ Intersection[array1, array2]  Except I want the position of the element when array2 = array1-1 instead of when array1 = array2. 2 added 276 characters in body edited Feb 28 at 4:26 MetallicSilence 2333 bronze badges I have two arrays, say array1 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; array2 = {13, 4, 6, 20, 21};  I want to compare these two arrays by cycling array1 through all elements in array2. The output should be the position in each array where they match a condition, where the condition array2 = array1[n]-1 is true. That is, the output should be: output = {6,2}  Because in array2, 5-1 = 4. (array1[6] = 5 and array2[2] = 4). So far, my code is output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ (I have no idea)  Where the code on the left hand side of Map gives me the positions of a true condition. On the right hand side of Map, I'm not sure what to do. To clarify a little bit, the code I want is similar to output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ Intersection[array1, array2]  Except I want the position of the element when array2 = array1-1 instead of when array1=array2 I have two arrays, say array1 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; array2 = {13, 4, 6, 20, 21};  I want to compare these two arrays by cycling array1 through all elements in array2. The output should be the position in each array where they match a condition, where the condition array2 = array1[n]-1 is true. That is, the output should be: output = {6,2}  Because in array2, 5-1 = 4. (array1[6] = 5 and array2[2] = 4). So far, my code is output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ (I have no idea)  Where the code on the left hand side of Map gives me the positions of a true condition. On the right hand side of Map, I'm not sure what to do. I have two arrays, say array1 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; array2 = {13, 4, 6, 20, 21};  I want to compare these two arrays by cycling array1 through all elements in array2. The output should be the position in each array where they match a condition, where the condition array2 = array1[n]-1 is true. That is, the output should be: output = {6,2}  Because in array2, 5-1 = 4. (array1[6] = 5 and array2[2] = 4). So far, my code is output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ (I have no idea)  Where the code on the left hand side of Map gives me the positions of a true condition. On the right hand side of Map, I'm not sure what to do. To clarify a little bit, the code I want is similar to output = {Position[array1, #][[1, 1]], Position[array2, #][[1, 1]]} & /@ Intersection[array1, array2]  Except I want the position of the element when array2 = array1-1 instead of when array1=array2 1 asked Feb 28 at 4:13 MetallicSilence 2333 bronze badges