albert's blog

2018/05/12

[snakeyaml] How to get rid of single quote in YAML when value is true / false?

Problem
The expected YAML is:

  intents:
  - greet
  - inform
  - others
  - question
  entities:
  - userid
  - is_account_locked
  - pass_company_check
  action_masking: true
  action_factory: remote
  actions:
  - utter_default
  - utter_greet
  - confirm:
      dependency:
        slots:
        - userid
  - unlock:
      dependency:
        slots:
        - userid
        - is_account_locked

Here has the original source code:

  package test.albert.snakeyaml;
  
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.yaml.snakeyaml.DumperOptions;
  import org.yaml.snakeyaml.Yaml;
  import org.yaml.snakeyaml.constructor.Constructor;
  import org.yaml.snakeyaml.nodes.Tag;
  import org.yaml.snakeyaml.representer.Representer;
  
  import lombok.AllArgsConstructor;
  import lombok.Data;
  import lombok.extern.slf4j.Slf4j;
  
  @Slf4j
  public class SnakeYamlTest {
  
      public static void main(String[] args) {
          // Set DumperOptions options
          DumperOptions options = new DumperOptions();
          options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
          options.setPrettyFlow(true);
  
          // overwrite Representer
          Representer representer = new Representer();
          representer.addClassTag(ActionAttribute.class, Tag.MAP);
  
          // Create Yaml instance with Representer and DumperOptions
          Yaml yaml = new Yaml(new Constructor(), representer, options);
  
          // Prepare map data for YAML
          Map<String, Object> actionMap1 = new HashMap<>();
          actionMap1.put("confirm", new ActionAttribute(new Dependency(Arrays.asList("userid"))));
  
          Map<String, Object> actionMap2 = new HashMap<>();
          actionMap2.put("unlock", new ActionAttribute(new Dependency(Arrays.asList("userid", "is_account_locked"))));
  
          Map<String, Object> map = new HashMap<>();
          map.put("intents", Arrays.asList("greet", "inform", "others", "question"));
          map.put("entities", Arrays.asList("userid", "is_account_locked", "pass_company_check"));
          map.put("action_factory", "remote");
          map.put("actions", Arrays.asList("utter_default", "utter_greet", actionMap1, actionMap2));
          map.put("action_masking", "true");
  
          // Serialize a Java object into a YAML String
          String output = yaml.dump(map);
          log.info("\n" + output);
      }
  
      @Data
      @AllArgsConstructor
      private static class ActionAttribute {
          Dependency dependency;
      }
  
      @Data
      @AllArgsConstructor
      private static class Dependency {
          private List<String> slots;
      }
  }

But the action_masking value had been added single quote to its front and rear, how to remove single quote?

  intents:
  - greet
  - inform
  - others
  - question
  entities:
  - userid
  - is_account_locked
  - pass_company_check
  action_masking: 'true'
  action_factory: remote
  actions:
  - utter_default
  - utter_greet
  - confirm:
      dependency:
        slots:
        - userid
  - unlock:
      dependency:
        slots:
        - userid
        - is_account_locked

How-To
According to snakeyaml source code, these values will regard as boolean value and add single quote from it front and rear

Therefore, you need to create a custom resolver to overwrite its value (remove true/false)

  package test.albert.snakeyaml;
  
  import org.yaml.snakeyaml.nodes.Tag;
  import org.yaml.snakeyaml.resolver.Resolver;
  
  public class CustomResolver extends Resolver {
      protected void addImplicitResolvers() {
          addImplicitResolver(Tag.BOOL, BOOL, "yYnNoO");
      }
  }

Then create Yaml instance with this custom resolver

  package test.albert.snakeyaml;
  
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.yaml.snakeyaml.DumperOptions;
  import org.yaml.snakeyaml.Yaml;
  import org.yaml.snakeyaml.constructor.Constructor;
  import org.yaml.snakeyaml.nodes.Tag;
  import org.yaml.snakeyaml.representer.Representer;
  
  import lombok.AllArgsConstructor;
  import lombok.Data;
  import lombok.extern.slf4j.Slf4j;
  
  @Slf4j
  public class SnakeYamlTest {
  
      public static void main(String[] args) {
          // Set DumperOptions options
          DumperOptions options = new DumperOptions();
          options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
          options.setPrettyFlow(true);
  
          // overwrite Representer
          Representer representer = new Representer();
          representer.addClassTag(ActionAttribute.class, Tag.MAP);
  
          // Create Yaml instance with Representer, DumperOptions, CustomResolver
          Yaml yaml = new Yaml(new Constructor(), representer, options, new CustomResolver());
  
          // Prepare map data for YAML
          Map<String, Object> actionMap1 = new HashMap<>();
          actionMap1.put("confirm", new ActionAttribute(new Dependency(Arrays.asList("userid"))));
  
          Map<String, Object> actionMap2 = new HashMap<>();
          actionMap2.put("unlock", new ActionAttribute(new Dependency(Arrays.asList("userid", "is_account_locked"))));
  
          Map<String, Object> map = new HashMap<>();
          map.put("intents", Arrays.asList("greet", "inform", "others", "question"));
          map.put("entities", Arrays.asList("userid", "is_account_locked", "pass_company_check"));
          map.put("action_factory", "remote");
          map.put("actions", Arrays.asList("utter_default", "utter_greet", actionMap1, actionMap2));
          map.put("action_masking", "true");
  
          // Serialize a Java object into a YAML String
          String output = yaml.dump(map);
          log.info("\n" + output);
      }
  
      @Data
      @AllArgsConstructor
      private static class ActionAttribute {
          Dependency dependency;
      }
  
      @Data
      @AllArgsConstructor
      private static class Dependency {
          private List<String> slots;
      }
  }

2018/05/11

[Angular] How to add serial number in ng-grid

Problem
If I would like to add serial number in ng-grid, how to do it?
I would like to implement in client side instead of server side.

The column configuration in ng-grid is as bellows:

  $scope.tab4.synonymCols  = [{
            field : 'value',
            displayName : 'value',
            cellClass : 'text-left',
            width : '25%'
        }, {
            field : 'synonyms',
            displayName : 'synonyms',
            cellClass : 'text-left',
            width : '70%'
        } ];

How-To
The updated column configuration in ng-grid is as bellows:

       $scope.tab4.synonymCols  = [{
            field : 'seq',
            displayName : 'no',
            cellClass : 'text-left',
            width : '5%',
            cellTemplate: '<div class="ngCellText ng-scope col1 colt1" ng-class="col.colIndex()"><span ng-cell-text="">{{row.rowIndex + 1}}</span></div>'
        }, {
            field : 'value',
            displayName : 'value',
            cellClass : 'text-left',
            width : '25%'
        }, {
            field : 'synonyms',
            displayName : 'synonyms',
            cellClass : 'text-left',
            width : '70%'
        } ];

2018/05/10

[Java] How to compute variance and standard deviation via Java

Problem
Assume I have a List of double, I would like to compute its variance and standard deviation.

How to implement it with Java?

How-To
Here has sample code:

    public static void main(String[] args) {
        List<Double> data = Arrays.asList(0.51, 0.53, 0.49, 0.74, 0.55, 0.47, 0.59, 0.47, 0.45, 0.72);
        DoubleSummaryStatistics summaryStatistics = data.stream().mapToDouble(d -> d.doubleValue()).summaryStatistics();
        Double mean = summaryStatistics.getAverage();

        Double variance = 0d;
        for (Double num : data) {
            variance += Math.pow(num - mean, 2);
        }
        variance = variance / 10;
        Double standardDeviation = Math.sqrt(variance);

        DecimalFormat df = new DecimalFormat("0.000");

        log.info("variance = " + df.format(variance));
        log.info("standardDeviation = " + df.format(standardDeviation));
    }

2018/05/09

[Microsoft Excel] 如何運用 Excel 計算出變異數 (variance) 與標準差 (standard deviation)

Problem
假設我有十筆資料

How-To
可以利用 Excel 內建的 varp 與 stdevp 計算出上述資料的變異數 (variance) 與標準差 (standard deviation)

2018/05/08

[Bootbox] How to set button focus in bootbox dialog

Problem
I am using Bootbox.js to create a custom dialog

The default behavior is focusing on the second button, i.e. EXCEL, how to I change its focus to the first button.

The code snippet is as bellows:

  $scope.doExport = function() {
     bootbox.dialog({
     message: "請選擇要匯出 JSON 或 Excel",
         title: '匯出',
         buttons: {
            json: {
                label: 'JSON',
                callback: function() {
                    $scope.exportJson();
                }
            },
            excel: {
                label: 'Excel',
                callback: function() {
                    $scope.exportExcel();
                }
            }
         }
     });
  };

How-To
You can simply add btn-primay class to the first button, the code snippet is as following:

   $scope.doExport = function() {
     bootbox.dialog({
         message: "請選擇要匯出 JSON 或 Excel",
         title: '匯出',
         buttons: {
             json: {
                 label: 'JSON',
                 className: 'btn-primary',
                 callback: function() {
                     $scope.exportJson();
                 }
             },
             excel: {
                 label: 'Excel',
                 callback: function() {
                     $scope.exportExcel();
                 }
             }
         }
     });
   };

Here has the updated dialog:

[Windows] Execute command every 10-sec in batch file

Problem
I would like to do two commands every 10 seconds via batch file in Windows:

 taskkill /IM test.exe /F
 del /F /Q C:\test\Bak\*.*

How to do it?

How-To
Here has the example:

:loop
 taskkill /IM test.exe /F
 del /F /Q C:\test\Bak\*.*
 timeout /t 10
 goto loop

2018/05/07

[Java] Use Apache Commons StringUtils.Replace Instead of String.replace

Quote

In general, the String.replace method works fine and is pretty efficient, especially if you’re using Java 9. But if your application requires a lot of replace operations and you haven’t updated to the newest Java version, it still makes sense to check for faster and more efficient alternatives.

Here has a simple experiments:

package your.simple.java;

import java.util.Calendar;
import java.util.Date;

import org.apache.commons.lang.StringUtils;

public class StringReplacementTest {

    private String test = "test";
    private int count = 100000000;

    public static void main(String[] args) {
        new StringReplacementTest().test1();
        new StringReplacementTest().test2();
    }

    public void test1() {
        Date from = Calendar.getInstance().getTime();
        for (int i = 0; i < count; i++) {
            test.replace("test", "simple test");
        }

        Date to = Calendar.getInstance().getTime();
        long seconds = (to.getTime() - from.getTime()) / 1000;
        System.out.println("[test1] seconds = " + seconds);
    }

    public void test2() {
        Date from = Calendar.getInstance().getTime();
        for (int i = 0; i < count; i++) {
            StringUtils.replace(test, "test", "simple test");
        }

        Date to = Calendar.getInstance().getTime();
        long seconds = (to.getTime() - from.getTime()) / 1000;
        System.out.println("[test2] seconds = " + seconds);
    }

}

Execution result:

[test1] seconds = 56
[test2] seconds = 9

Reference
[1] https://dzone.com/articles/11-simple-java-performance-tuning-tips?edition=334833&utm_source=Daily%20Digest&utm_medium=email&utm_campaign=Daily%20Digest%202017-11-03

2018/05/06

[JavaScript] Utilize window.getSelection to get selected text

Problem
If I would like to get the selected text from a TextField via JavaScript, how to do it?

How-To
You can make good use of window.getSelection to fulfill this requirement.

HTML code snippet:

       <div class="row">
           <div class="col-sm-offset-1 col-sm-10">
             <div class="form-group">
               <label for="operaName" class="control-label">連續劇</label>
               <input type="text" class="form-control input-lg" id="operaName" data-ng-model="operaName" 
                      data-ng-mouseup="showOperaSelectedText()" >
             </div>
             <div class="form-group">
              <label class="control-label">起訖</label>
              <span> {{operaNameFromIndex}} ~ {{operaNameToIndex}}</span>
             </div>
             <div class="form-group">
                 <label class="control-label">選擇文字</label>
                 <span> {{operaNameSelected}}</span>
             </div>
           </div>
       </div>

JavaScript code snippet:

     $scope.operaName = "又，吳海英";
     $scope.operaNameFromIndex = 0;
     $scope.operaNameToIndex = 0;
     $scope.operaNameSelected = '';
      
     $scope.showOperaSelectedText = function() {
     // if selected
     if (window.getSelection) {
          // get selected text
          $scope.operaNameSelected = window.getSelection().toString();
          // get from index
          $scope.operaNameFromIndex = $('#operaName').prop('selectionStart');
          // get end index
         $scope.operaNameToIndex = $('#operaName').prop('selectionEnd');
         }
     }

Screenshot:

2018/05/05

[Angular] How to show data via ng-repeat in horizontal ?

Problem
Assume I have an String array.

    $scope.names = ['朴道京', '吳海英', '李振尚', '朴秀京', '朴勳'];

I would like to show these names in HTML page via ng-repeat, here has the code snippet:

    <div class="row">
      <div class="col-sm-offset-1 col-sm-4">
         <div data-ng-repeat="name in names">
               <span>{{name}}</span>
         </div>
      </div>
    </div>

But it display in vertical way, how to display in horizontal way?

How-To
Use span instead of div, the updated code snippet are as bellows:

   <div class="row">
     <div class="col-sm-offset-1 col-sm-4">
        <span data-ng-repeat="name in names">
              <span>{{name}}</span>
        </span>
     </div>
   </div>

Here has the screenshot:

2018/05/04

[閱讀筆記] The Little Book That Builds Wealth (4/7)

追求成長不一定都是好的。公司應該在自己擅長的領域賺錢與分享利潤給股東，不要將所賺得的利潤投入沒有護城河與未知的產業。Microsoft 有本錢這樣玩 (如成立Actimates 用來販售一系列的小孩玩具，又如成立 cable news chaneel 提供新聞服務等)，但是大部分的公司並沒有這樣的本錢
有些產業競爭非常激烈，非常難以建立起獨特的競爭優勢；有些產業則相對沒這麼競爭，即便是普通的公司也可以維持穩固的資本回報。身為投資人，你應該選擇後者來投資
Morningstar 將護城河分成兩類，公司擁有非常持久且強大的競爭優勢，稱為 wide moat；另外，公司所擁有的競爭優勢並非相當強大，則稱為 narrow moat
當成本是最重要的事情時，在此產業就很難挖掘出護城河。無論你是在挖掘金屬礦物、製造化學原料、生產鋼鐵等，這些都非常難以做出差異化，導致你的客戶只在乎誰最便宜
如何衡量企業的獲利能力呢？計算企業投入多少錢，以及獲得多少利潤，獲得的利潤越高，代表這個產品或服務就會好。即投入的資金轉換為獲利的效率
衡量資本回報率的幾個指標

資產回報率（ROA, Return On Assets）：

ROA 衡量的是每一塊錢的資產替公司產生多少收入
ROA 的視角實際上是從資產負債表的左側去看，從資產的角度衡量回報，而並不關注資本結構。資產收益率 = 凈利潤 / 總資產總額

凈資產回報率（ROE, Return On Equity）：ROE的視角是從股東的角度看問題，單純從股權的角度衡量回報，而不考慮公司的資本結構及負債情況。凈資產收益率 = 稅後利潤 / 所有者權益。假定某公司年度稅後利潤為2億元，年度平均凈資產為15億元，則其本年度之凈資產收益率就是13．33%（即(2億元/15億元)*100%）。
投入資本回報率（ROIC, Return On Invested Capital）：

ROIC是從資本的角度看問題，綜合考慮股權與債權，衡量投資的效率。與ROIC對應的是平均資金成本（WACC）。如果ROIC小於WACC，就說明投入資本的回報小於平均資本成本，公司是在浪費資本。ROIC=息稅前收益（EBIT）*（1-稅率）/ 投入資本
ROIC 計算相當複雜且不像 ROA、ROE這麼容易取得

ROE 的缺點是，越會借錢的公司，ROE 就會越高，所以當你用 ROE 在分析企業的資本回報，記得留意公司的負債
有些產業在結構上就是比其他產業更賺錢，其一定較容易建立起護城河。你應該把錢投資在這種產業
有些產業就是比其他產業更容易建立起競爭優勢，人生本來就不公平
護城河是絕對的，不是相對的。結構上較具吸引力的產業的第四名的公司，與殺得你死我活的最佳的公司相較之下，前者一定擁有較寬廣的護城河
所謂的優秀企業，是指『更容易長期產生高資本報酬率的企業』
公司經營者的表現，沒有想你的這麼重要
企業的長期競爭優勢源自於結構化的企業特色，包含無形資產 (intangible assets)、轉換成本 (switching costs)、網絡效應 (network economics)、與成本優勢 (cost advantage)，公司經營者對於這幾點的影響力微乎極危微
新創公司的投資人，應將分析比重主要放在新創公司所投入的事業，而非新創公司的管理團隊
公司的結構化特性 (structural characteristics) 對於企業的長期競爭優勢有巨大的影響，管理者的決策則鮮少造成影響
賽馬時，你該賭的是馬，而非騎師 (bet on the horse, not the jockey)
一個 CEO ，很難建立起不存在的競爭優勢，或是摧毀一開始就建立起來很強壯的競爭優勢
在沒有護城河、深陷紅海競爭的企業，為了克服更大的困難來獲得成功，的確需要優秀的管理者，才有機會獲得困難的競爭優勢，如 Starbucks、Dell、Nucor (紐克鋼鐵) 等。若是在擁有寬廣、強大的護城河的公司，CEO 的重要性就不是這麼高了
儘管說，好的 CEO 可以增加企業的價值，但是管理本身並無法建立可持續的競爭優勢
管理雖然重要，但是其重要性遠低於護城河
你該投資一家平庸的 CEO 但是擁有寬廣護城河的公司，而非投資一間由 superstar 所管理但是沒有護城河的公司。長期來說，前者可以提供較高的成功機率
尋找護城河流程

零售業與連鎖餐廳的客戶轉換成本（switching costs）非常低，所以在此產業中的企業必須建立起規模、擁有良好信譽的品牌或其他可以防禦的優勢，才能擁有護城河。若沒有護城河，現在的高資本報酬率（returns on capital），很快就會消失
檢視一家公司是否擁有經濟護城河，第一步是檢查產生資本回報的歷史紀錄。強勁的資本回報率代表公司可能擁有護城河，平庸或差勁的資本回報率代表公司缺乏競爭優勢
若一家企業擁有強勁的資本回報率，還需確認其是否有能力繼續維持這樣的績效表現。採用競爭優勢分析工具，如無形資產 (intangible assets)、轉換成本 (switching costs)、網絡效應 (network economics)、與成本優勢 (cost advantage)，試著找出企業的護城河。若你無法找出維持優異的資本回報率的原因，這家公司可能不具備護城河

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