大约有 850 项符合查询结果(耗时:0.0229秒) [XML]

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How do I compute derivative using Numpy?

...the derivative in a single point, the formula would be something like x = 5.0 eps = numpy.sqrt(numpy.finfo(float).eps) * (1.0 + x) print (p(x + eps) - p(x - eps)) / (2.0 * eps * x) if you have an array x of abscissae with a corresponding array y of function values, you can comput approximations o...
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MySQL “Group By” and “Order By”

...o do this at the very bottom of this link. http://dev.mysql.com/doc/refman/5.0/en/group-by-hidden-columns.html If you can get am insert/update event (like a trigger) to pre-compute the concatenation of the fields you can index it and the query will be as fast as if the group by was over just the fi...
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创业第一年 太特么累了 - 资讯 - 清泛网 - 专注C/C++及内核技术

...流畅,但后来发现有的手机特别卡,试了半天总结出安卓5.0以上都这毛病,找原因吧。。。呵呵,到现在也没找到!技术总监已咬碎牙准备换框架了。还有与外包团队的对接和功能整合,绝对是件麻烦事,有时觉得应该都明白就...
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Unsupported major.minor version 52.0 [duplicate]

...= 54 Java SE 9 = 53 Java SE 8 = 52 Java SE 7 = 51 Java SE 6.0 = 50 Java SE 5.0 = 49 JDK 1.4 = 48 JDK 1.3 = 47 JDK 1.2 = 46 JDK 1.1 = 45 These are the assigned major numbers. The error regarding the unsupported major.minor version is because during compile time you are using a higher JDK and a lower...
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ERROR: Error installing capybara-webkit:

...G: The next major version of capybara-webkit will require at least version 5.0 of Qt. You're using version 4.8.6. Instead, if you do brew install qt5 brew link --force qt5 you won't get that error. share | ...
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How do you implement an async action delegate method?

...5C35.8209 11.5455 35.4954 10.8521 35.4954 9.60062V6.59049C35.4954 5.28821 35.0173 4.66232 34.0034 4.66232C32.9703 4.66232 32.492 5.28821 32.492 6.59049V10.1419Z\" /\u003e\u003cpath fill-rule=\"evenodd\" clip-rule=\"evenodd\" d=\"M25.6622 17.6335C27.8049 17.6335 29.3739 16.9402 30.2537 15.6379C30.846...
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You need to use a Theme.AppCompat theme (or descendant) with this activity

...eme.AppCompat. That should work. I had the same problem after upgrading to 5.0 on my device and ended up setting @style/Theme.AppCompat.Light as the theme on my activity. Something not right here... – speedynomads Nov 18 '14 at 0:21 ...
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JavaScript: How to find out if the user browser is Chrome?

...lman here: my Android Chrome user agent contains the "OPR" string! Mozilla/5.0 (Linux; Android 8.0.0; ASUS_Z012D Build/OPR1.170623.026) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.109 Mobile Safari/537.36, therefore isChrome() returns false. – Frosty Z ...
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UIButton: Making the hit area larger than the default hit area

...intInside:(CGPoint)point withEvent:(UIEvent *)event { CGFloat margin = 5.0; CGRect area = CGRectInset(self.bounds, -margin, -margin); return CGRectContainsPoint(area, point); } share | ...
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What is the use of ObservableCollection in .net?

... From Pro C# 5.0 and the .NET 4.5 Framework The ObservableCollection<T> class is very useful in that it has the ability to inform external objects when its contents have changed in some way (as you might guess, working with ReadOnl...