indexing

问题 We are aware that the standard method of setting a single cell is using at or iat . However, I noticed some interesting behaviour I was wondering if anyone could rationalise. In solving this question, I come across some weird behaviour of loc . # Setup. pd.__version__ # '0.24.0rc1' df = pd.DataFrame({'A': [12, 23], 'B': [['a', 'b'], ['c', 'd']]}) df A B 0 12 [a, b] 1 23 [c, d] To set cell (1, 'B'), it suffices to do this with at, like df.at[1, 'B'] = ... . But with loc, I initially tried this

问题 I have a MySQL database that runs for some time now with many changes on it. Lately I looked over it and I noticed that in some cases I have doubled the index on the same field. Some Indexes are missing, and in general there is a huge mess in all the indexes. I wants to drop all indexes from a table. Later on I have a prepared script that will run ALTER TABLE and add the relevant indexes. Is there a way to drop all indexes from a table? 回答1: If you have phpmyadmin or any similar tool you can

问题 I have a table with a few hundred thousand lines. (It’s a precomputed table expressing the relation between lemmas of words and other big tables.) I need to do multiple selections to find a combination of different entries, i.e. I have to use “AS” to do select … from ltc as l0, ltc as l1, ltc as l2 … order by ... The speed of the query depends on the sorting: Without sorting, it’s a few milliseconds, with sorting, it can take a few minutes. This is due, as far as I can tell, to the temporary

问题 I have a table with a few hundred thousand lines. (It’s a precomputed table expressing the relation between lemmas of words and other big tables.) I need to do multiple selections to find a combination of different entries, i.e. I have to use “AS” to do select … from ltc as l0, ltc as l1, ltc as l2 … order by ... The speed of the query depends on the sorting: Without sorting, it’s a few milliseconds, with sorting, it can take a few minutes. This is due, as far as I can tell, to the temporary

问题 The question is similar to (Update) Add index column to data.frame based on two columns Here my example data.frame: df = read.table(text = 'ID Day Count Count_group 77661 14498 4 5 76552 14498 4 5 37008 14498 4 5 34008 14498 4 5 30004 14497 1 5 30004 14497 1 4 28047 14496 3 4 28049 14496 3 4 29003 14496 3 4 69012 14468 1 4 69007 14467 3 4 69012 14467 3 4 69020 14467 3 4 42003 13896 2 4 42011 13896 2 4 22001 13895 2 4 23007 13895 2 4 28047 14496 3 3 28049 14496 3 3 29003 14496 3 3 69007 14467

问题 I've a list of empty divs and dynamically inserting a background image – so at first, their background-image: url(); property is completely empty. With some event, it's background-image url loads into the previously empty background-image: url(); tag. The url of the appearing background-image is temporarily stored in the "alt" tag of the div: <div style='background-image: url();' alt='http://something...'></div> . I'm doing so to get round corners on several animated gifs without using

问题 I have solr 3.6.2 installed on my machine, perfectly running with tomcat. I want to index a wikipedia dump file using solr. How do I do this using DataImportHandler? Any other way? I don't have any knowledge of xml. The file I have mentioned has size of around 45GB when extracted. Any help would be greatly appreciated. Update- I tried doing whats said on the DataImportHandler page. But there is some error maybe because their version of solr is much older. My data.config- <dataConfig>

问题 I have an excel formula, which is supposed to work but returns #VALUE and I cannot figure out why. I have this table: A B 1 | | | 2 | Oranges | 1 | 3 | Apples | 2 | 4 | Grapes | 3 | 5 | Oranges | 4 | 6 | Apples | 5 | 7 | Grapes | 6 | 8 | Apples | 7 | I want to Check for matching values in Column A like "Apples", "Oranges", etc. and return all the corresponding values from Column B in one row: The output should be like this but I only get #VALUE: A B C D 11 | Apples | 2 | 5 | 7 | 12 | Oranges

问题 I have an excel formula, which is supposed to work but returns #VALUE and I cannot figure out why. I have this table: A B 1 | | | 2 | Oranges | 1 | 3 | Apples | 2 | 4 | Grapes | 3 | 5 | Oranges | 4 | 6 | Apples | 5 | 7 | Grapes | 6 | 8 | Apples | 7 | I want to Check for matching values in Column A like "Apples", "Oranges", etc. and return all the corresponding values from Column B in one row: The output should be like this but I only get #VALUE: A B C D 11 | Apples | 2 | 5 | 7 | 12 | Oranges

问题 I'm having trouble, because I have this image, what I want to do is just work with the pixels that aren't black. But I have to find the first and last nonzero values to define the boundaries were I will work, the problem is that I can find the first nonzero values(rowandcolumn), but in the last for the column appears the value 1799,and my image is 499x631x3 uint8 , and it should be 533. What is the problem?? My code below: %Find where the image begins and starts [r_min, c_min]=find