indexing

问题 I am new to MATLAB. I have a data structure named da . I want to sort the first column of da.mat and want to let da.rid and the other columns to follow the rearranged order. da.cid contains the column names and da.rid contains the row IDs. da = mat: [22268x377 single] rid: {22268x1 cell} rhd: {''} rdesc: {22268x1 cell} cid: {377x1 cell} chd: {0x1 cell} cdesc: {377x0 cell} Also, if I want to use some other column instead of the first column of da.mat and which I will get from da.cid , how can

问题 unsigned char changeValue(unsigned char pArray[256],unsigned char value) { return pArray[value]; } how can I change this function with neon with about uint8x8_t?? thanks for your help!! 回答1: You can't - NEON does not have gathered loads. The only case that you can handle like this is when you want to return 8 or 16 contiguous byte values. 来源： https://stackoverflow.com/questions/11502332/arm-neon-how-can-i-change-value-with-a-index

问题 NSMutableArray *tmpMutArr = [NSMutableArray arrayWithArray:allObjectsArray]; NSLog(@"The content of array is%@",tmpMutArr); int index; for (int i=0;i<[tmpMutArr count];i++) { if([[tmpMutArr objectAtIndex:i] isKindOfClass:[NSDictionary class]]) { NSMutableDictionary *tempDict = [tmpMutArr objectAtIndex:i]; if([[tempDict valueForKey:@"Name"] isEqualToString:[NSString stringWithFormat:@"%@", nameString]]) { index = i; } } } [tmpMutArr replaceObjectAtIndex:index withObject:[NSDictionary

问题 I have a mysql query that gets a list of private messages where a user is either the sender, or receiver. SELECT users_user1.user_name AS pm_username_1, users_user1.user_avatar AS pm_username_1_avatar, users_user2.user_name AS pm_username_2, users_user2.user_avatar AS pm_username_2_avatar, pms.* FROM pm pms LEFT JOIN users users_user1 ON users_user1.user_id = pms.pm_sender LEFT JOIN users users_user2 ON users_user2.user_id = pms.pm_receiver WHERE pm_thread = pm_id AND (pm_receiver = '1' OR pm

问题 I have a query (which was created by LINQ to SQL) to get me a list of 'site visits' that were made between a certain date range which resulted in an order (orderid is not null). Theres nothing wrong with the query. I just need advice on creating the correct index for it. I was playing around trying different combinations on a production site and managed to screw things up such that a foreign key got disconnected. I fixed that after some panic - but thought I'd ask for advice now before

问题 I have a problem with creating index for my query and can't find any similar solution on the web, so maybe some of you will help me. To simplify problem let's say we have Phones with some attributes, { "type":"Samsung", "model":"S3", "attributes":[{ "value":"100", "name":"BatteryLife" },{ "value":"200$", "name":"Price" } } With index: {"type":1, "attributes.value":1} We have millions of phones for every type and i want to find phones for given type that have given attributes, my query looks

问题 I'm trying to index some matrix, y , and then reindex that result with some boolean statement and set the corresponding elements in y to 0 . The dummy code I'm using to test this indexing scheme is shown below. x=np.zeros([5,4])+0.1; y=x; print(x) m=np.array([0,2,3]); y[0:4,m][y[0:4,m]<0.5]=0; print(y) I'm not sure why it does not work. The output I want: [[ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1]] [[ 0. 0.1 0. 0. ] [ 0. 0.1 0. 0. ] [ 0. 0

问题 I'm trying to index some matrix, y , and then reindex that result with some boolean statement and set the corresponding elements in y to 0 . The dummy code I'm using to test this indexing scheme is shown below. x=np.zeros([5,4])+0.1; y=x; print(x) m=np.array([0,2,3]); y[0:4,m][y[0:4,m]<0.5]=0; print(y) I'm not sure why it does not work. The output I want: [[ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1] [ 0.1 0.1 0.1 0.1]] [[ 0. 0.1 0. 0. ] [ 0. 0.1 0. 0. ] [ 0. 0

问题 I have got a question refering to one of my last issues: Keep upper n rows of a pandas dataframe based on condition. Using the second suggested answer my code looks like that: import pandas as pd x=2 y=2 df2 = pd.DataFrame({'x':[1,2,3,4], 'y':[2,2,2,2],'id':[1,2,3,4]}) df2_cut=df2[df2.index <= (df2[(df2.x == x) & (df2.y == y)]).index.tolist()] This works fine too, it is just the same but having another dataframe there. import pandas as pd x=2 y=2 df1 = pd.DataFrame({'x':[2,2,2,2], 'y':[1,2,3

问题 This is what I have so far. It throws an exception when I try to access an index out of bounds. I tried to say "return NULL" if the range is out of bounds for the overloaded subscript operator, but it's not working. The problem is when I try to assign a value to an index above the upper limit it allows it to happen. Like with the current code if I change the "< 8" in the main function to "< 9", it uses array element 8 without problem, but I want it to have a problem with that. Any help is