Day 40, 2020-10-03Day 37&38&39, 2020-09-30 & 2020-10-01 & 2020-10-02Day 35 & Day 36, 2020-09-28 & 2020-09-29Day 34, 2020-09-27Day 33, 2020-09-26Day 32 (Task 10), 2020-09-25Day 31 (9-2-10), 2020-09-24Day Thirty (A puzzle to be solved), 2020-09-22Day Twenty Nine, 2020-09-22Day Twenty-Eight (Task 9-2-9), 2020-09-21Day Twenty-Seven, 2020-09-20Day Twenty Six, 2020-09-19Day Twenty Five, 2020-09-18Day Twenty Four, 2020-09-17Day Twenty Three (Task 9-2), 2020-09-16Day Twenty Two (Task 9-1 continued), 2020-09-15Day Twenty-One (Task 9-1 continued), 2020-09-14Day Twenty (Task 8 Continued + Task 9-1), 2020-09-13Day Nineteen (Task 8), Spet. 12, 2020Day Eighteen (Task 7-1-10, 11, Sept. 11, 2020Day Fourteen, Fifteen, Sixteen & Seventeen, Spet. 07 ~ 10, 2020Day Thirteen (Task 7-1), 2020-09-06Day Twelve, Sept. 5, 2020: ScalesDay Eleven, Sept.4th, 2020Day Ten (Task 6-6), Sept. 3rd, 2020Day Eight, Spet. 1, 2020Day Six, 30 Aug 2020Day Five, 29 Aug 2020Day Four, 28 Aug 2020Day Three, 27 Aug 2020Day 1 & Day 2, 25 Aug. & 26 Aug., 2020, Basic Commands
Day Nine, 2020-09-02
md`# Day Nine, 2020-09-02`
md` ## Redoing yesterday's exercise:
### Task 6-1
- 6-1-1:
- To specify the height of each bar, I should use \`.style()\`, rather than \`.attr()\`. In \`D3.js\`, \`.style()\` is to assign CSS styles to a HTML element. In CSS, we won't use \`style\` because everything is \`style()\`. In HTML, we do use it. For example, \` <div style="height: 75px;"></div>"\`;
- To make the height of each bar correspondes to its data value, I should use \`function(d){return d + "px"}\` rather than \`function(d){return d }\`;
- 6-1-2: To add some space (2px) between bars, I need to use \`margin-right: 2px\` in the CSS (\`div.bar{}\`. To learn more about the differences between \`padding\`, \`border\`, \`margin\`, read [this amazing tutorial](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Box_Model/Introduction_to_the_CSS_box_model);
- 6-1-3:
- First, I need to initilize an empty array using \`dataset = []\`
- In Javascript, \`Math\` is [a global object](https://www.w3schools.com/js/js_math.asp), whereas \`.push()\` is [an array method](https://www.w3schools.com/js/js_array_methods.asp).
- A \`for\` loop: \`for (initialization; test; updata){
}\`
`
md`### Task 6-2
- 6-2-4
- When drawing five circles, we used three terms, "svg", "circles", and "circle", which of them should be fixed, and which can be random? "svg" and "circle" should be fixed, but "circles" can be random;
- One thing I still don't understand is that in Task 6-1-1, I have to use \`function(d){return d + "px"}\` rather than \`function(d){return d }\`. However, in Task 6-2-4, using \`.attr("r", function(d){return d
})\` is fine, and in \`.attr("cy", h/2)\`, I don't need to put \`""\` to enclose \`h/2\`. I guess it's because of **the differences between \`.style()\` and \`.attr()\`**. But **how different? I don't know.**;
- When we need the index of the data values, we should use \`function(d,i){}\` even if we don't need the \`d\`. However, when we only need the \`d\`, we can simply use \`function(d){}\`.
- 6-2-6: Again, we need to add \`px\` in \`style\`
`
md`### Task 6-3
To change the color of bars, we need to use \`.attr("fill", "teal")\`, rather than \`.style()\`.
`
md` ## New knowlege today
- I kind of feel that in \`.attr()\`, if the input should be numbers, then we don't need put quotations marks to enclose this input. For example, \`.attr("height", X)\` or, \`.attr("y", Y)\`. However, in \`.attr("fill", "YourColorChoice"\`, we do need to use quotation marks.
`
md`## Task 6-4
- Based on Task 6-3, change the color of the bars using RGB. Let red and green components be fixed at zero. Let the blue component be the corresponding data value times 10, which then is rounded to the nearest whole number (using \`Math.round()\`)
- **I still do not understand why we should put the codes in between \`"+ +"\`. This is so difficult for me**.
`
md`### Task 6-5
- 6-5-1. Add value labels on top of each bar;
- 6-5-2. Move each value label down by 15 pixels and to the right by 5 pixels; Style the font. Use sans-serif, 11px, and in white.
`
md`p. 109`
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