<?xml version="1.0" encoding="utf-8"?><feed xmlns="http://www.w3.org/2005/Atom" ><generator uri="https://jekyllrb.com/" version="3.10.0">Jekyll</generator><link href="https://coolest-tomato.github.io/feed.xml" rel="self" type="application/atom+xml" /><link href="https://coolest-tomato.github.io/" rel="alternate" type="text/html" /><updated>2025-02-23T00:02:54+00:00</updated><id>https://coolest-tomato.github.io/feed.xml</id><title type="html">The Coolest Tomato’s Blog</title><subtitle>CU Boulder, ECEN</subtitle><author><name>Shim, 심장현</name></author><entry><title type="html">Discrete_convoltuion</title><link href="https://coolest-tomato.github.io/Discrete_Convoltuion/" rel="alternate" type="text/html" title="Discrete_convoltuion" /><published>2025-02-22T00:00:00+00:00</published><updated>2025-02-22T00:00:00+00:00</updated><id>https://coolest-tomato.github.io/Discrete_Convoltuion</id><content type="html" xml:base="https://coolest-tomato.github.io/Discrete_Convoltuion/"><![CDATA[<div class="language-python highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="n">np</span>
<span class="kn">import</span> <span class="nn">matplotlib.pyplot</span> <span class="k">as</span> <span class="n">plt</span>

<span class="c1"># Define x[n] and h[n]
</span><span class="n">n_x</span> <span class="o">=</span> <span class="n">np</span><span class="p">.</span><span class="n">arange</span><span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="mi">8</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span>  <span class="c1"># x[n] is 1 for 3 ≤ n ≤ 8
</span><span class="n">x_n</span> <span class="o">=</span> <span class="n">np</span><span class="p">.</span><span class="n">ones</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">n_x</span><span class="p">))</span>

<span class="n">n_h</span> <span class="o">=</span> <span class="n">np</span><span class="p">.</span><span class="n">arange</span><span class="p">(</span><span class="mi">4</span><span class="p">,</span> <span class="mi">15</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span>  <span class="c1"># h[n] is 1 for 4 ≤ n ≤ 15
</span><span class="n">h_n</span> <span class="o">=</span> <span class="n">np</span><span class="p">.</span><span class="n">ones</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">n_h</span><span class="p">))</span>

<span class="c1"># Compute convolution y[n] = x[n] * h[n]
</span><span class="n">y_n</span> <span class="o">=</span> <span class="n">np</span><span class="p">.</span><span class="n">convolve</span><span class="p">(</span><span class="n">x_n</span><span class="p">,</span> <span class="n">h_n</span><span class="p">)</span>

<span class="c1"># Compute the range for n (convolution range)
</span><span class="n">n_y</span> <span class="o">=</span> <span class="n">np</span><span class="p">.</span><span class="n">arange</span><span class="p">(</span><span class="n">n_x</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">+</span> <span class="n">n_h</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="n">n_x</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="o">+</span> <span class="n">n_h</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span>

<span class="c1"># Plot the result
</span><span class="n">plt</span><span class="p">.</span><span class="n">stem</span><span class="p">(</span><span class="n">n_y</span><span class="p">,</span> <span class="n">y_n</span><span class="p">,</span> <span class="n">basefmt</span><span class="o">=</span><span class="s">" "</span><span class="p">)</span>
<span class="n">plt</span><span class="p">.</span><span class="n">xlabel</span><span class="p">(</span><span class="s">'n'</span><span class="p">)</span>
<span class="n">plt</span><span class="p">.</span><span class="n">ylabel</span><span class="p">(</span><span class="s">'y[n]'</span><span class="p">)</span>
<span class="n">plt</span><span class="p">.</span><span class="n">title</span><span class="p">(</span><span class="s">'Convolution y[n] = x[n] * h[n]'</span><span class="p">)</span>
<span class="n">plt</span><span class="p">.</span><span class="n">grid</span><span class="p">()</span>
<span class="n">plt</span><span class="p">.</span><span class="n">show</span><span class="p">()</span>
</code></pre></div></div>

<p>​  <br />
<img src="https://coolest-tomato.github.io\images\2025-02-22-HW4_2\스크린샷 2025-02-22 100733.png" alt="스크린샷 2025-02-22 100733" /></p>]]></content><author><name>Shim, 심장현</name></author><summary type="html"><![CDATA[```python import numpy as np import matplotlib.pyplot as plt]]></summary></entry><entry><title type="html">Electromagnetism_1</title><link href="https://coolest-tomato.github.io/Electromagnetism_1/" rel="alternate" type="text/html" title="Electromagnetism_1" /><published>2025-02-18T00:00:00+00:00</published><updated>2025-02-18T00:00:00+00:00</updated><id>https://coolest-tomato.github.io/Electromagnetism_1</id><content type="html" xml:base="https://coolest-tomato.github.io/Electromagnetism_1/"><![CDATA[<div class="language-python highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="n">np</span>
<span class="kn">import</span> <span class="nn">matplotlib.pyplot</span> <span class="k">as</span> <span class="n">plt</span>
<span class="kn">import</span> <span class="nn">math</span>
</code></pre></div></div>

<div class="language-python highlighter-rouge"><div class="highlight"><pre class="highlight"><code>
<span class="c1"># parameters for v(x) 
</span><span class="n">pho1</span> <span class="o">=</span> <span class="mf">0.2</span>         <span class="c1"># volume charge density 
</span><span class="n">pho2</span> <span class="o">=</span> <span class="mf">0.1</span>
<span class="n">pho3</span> <span class="o">=</span> <span class="mf">0.05</span>
<span class="n">pho4</span> <span class="o">=</span> <span class="mf">0.01</span>
<span class="c1"># if pho increases, shape is getting more sharp
</span><span class="n">er</span> <span class="o">=</span> <span class="mf">3.8</span>        <span class="c1"># SiO2 permittivity
</span><span class="n">e0</span> <span class="o">=</span> <span class="mf">8.854e-12</span>
<span class="n">e</span>  <span class="o">=</span> <span class="n">e0</span> <span class="o">*</span> <span class="n">er</span> 
<span class="n">distance</span> <span class="o">=</span> <span class="mf">100e-6</span> <span class="c1"># distance between plates 
</span><span class="n">V_0</span> <span class="o">=</span> <span class="mi">5</span> <span class="c1"># 5 volts at x = 0
</span><span class="n">V_d</span> <span class="o">=</span> <span class="mi">0</span> <span class="c1"># ground at x = distance
</span></code></pre></div></div>

<div class="language-python highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="n">C2</span> <span class="o">=</span> <span class="mi">5</span>
<span class="k">def</span> <span class="nf">potential_pho1</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho1</span><span class="p">,</span> <span class="n">C2</span><span class="p">):</span>
    <span class="k">return</span> <span class="o">-</span><span class="p">(</span><span class="n">pho1</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">))</span><span class="o">*</span><span class="p">(</span><span class="n">x</span><span class="o">**</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">C1_pho1</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">C2</span> 
<span class="k">def</span> <span class="nf">potential_pho2</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho2</span><span class="p">,</span> <span class="n">C2</span><span class="p">):</span>
    <span class="k">return</span> <span class="o">-</span><span class="p">(</span><span class="n">pho2</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">))</span><span class="o">*</span><span class="p">(</span><span class="n">x</span><span class="o">**</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">C1_pho2</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">C2</span>
<span class="k">def</span> <span class="nf">potential_pho3</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho3</span><span class="p">,</span> <span class="n">C2</span><span class="p">):</span>
    <span class="k">return</span> <span class="o">-</span><span class="p">(</span><span class="n">pho3</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">))</span><span class="o">*</span><span class="p">(</span><span class="n">x</span><span class="o">**</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">C1_pho3</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">C2</span>
<span class="k">def</span> <span class="nf">potential_pho4</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho4</span><span class="p">,</span> <span class="n">C2</span><span class="p">):</span>
    <span class="k">return</span> <span class="o">-</span><span class="p">(</span><span class="n">pho4</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">))</span><span class="o">*</span><span class="p">(</span><span class="n">x</span><span class="o">**</span><span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="n">C1_pho4</span><span class="o">*</span><span class="n">x</span> <span class="o">+</span> <span class="n">C2</span>

<span class="c1"># It would be more comfortable if using array
# for example, pho = [0.2, 0.1, 0.05, 0.01] and C1 = [ ~ ]
# Then make subplot using i, j as you can see below 
</span>
<span class="n">C1_pho1</span> <span class="o">=</span> <span class="p">(</span><span class="n">pho1</span><span class="o">*</span><span class="n">distance</span><span class="p">)</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">)</span> <span class="o">-</span> <span class="p">(</span><span class="mi">5</span><span class="o">/</span><span class="n">distance</span><span class="p">)</span> <span class="c1"># pho1,2,3,4 -&gt; Fixing codes in a simpler way 
</span><span class="n">C1_pho2</span> <span class="o">=</span> <span class="p">(</span><span class="n">pho2</span><span class="o">*</span><span class="n">distance</span><span class="p">)</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">)</span> <span class="o">-</span> <span class="p">(</span><span class="mi">5</span><span class="o">/</span><span class="n">distance</span><span class="p">)</span>
<span class="n">C1_pho3</span> <span class="o">=</span> <span class="p">(</span><span class="n">pho3</span><span class="o">*</span><span class="n">distance</span><span class="p">)</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">)</span> <span class="o">-</span> <span class="p">(</span><span class="mi">5</span><span class="o">/</span><span class="n">distance</span><span class="p">)</span>
<span class="n">C1_pho4</span> <span class="o">=</span> <span class="p">(</span><span class="n">pho4</span><span class="o">*</span><span class="n">distance</span><span class="p">)</span><span class="o">/</span><span class="p">(</span><span class="mi">2</span><span class="o">*</span><span class="n">e</span><span class="p">)</span> <span class="o">-</span> <span class="p">(</span><span class="mi">5</span><span class="o">/</span><span class="n">distance</span><span class="p">)</span>
</code></pre></div></div>

<div class="language-python highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="n">x</span> <span class="o">=</span> <span class="n">np</span><span class="p">.</span><span class="n">linspace</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">distance</span><span class="p">,</span> <span class="mi">500</span><span class="p">)</span>
</code></pre></div></div>

<div class="language-python highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c1"># Making subplot for four values of rho 
</span><span class="n">figure</span><span class="p">,</span> <span class="n">axis</span> <span class="o">=</span> <span class="n">plt</span><span class="p">.</span><span class="n">subplots</span><span class="p">(</span><span class="mi">2</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="n">figsize</span><span class="o">=</span><span class="p">(</span><span class="mi">10</span><span class="p">,</span> <span class="mi">8</span><span class="p">),</span> <span class="n">constrained_layout</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span>

<span class="c1"># i, j = divmod(idx, 2)  # 2x2 subplot, calculate indexes
</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">].</span><span class="n">plot</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">potential_pho1</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho1</span><span class="p">,</span> <span class="n">C2</span><span class="p">))</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">].</span><span class="n">set_title</span><span class="p">(</span><span class="sa">f</span><span class="s">"pho = </span><span class="si">{</span><span class="n">pho1</span><span class="si">}</span><span class="s">"</span><span class="p">)</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">].</span><span class="n">set_xlabel</span><span class="p">(</span><span class="s">"distance (m)"</span><span class="p">)</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">].</span><span class="n">plot</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">potential_pho2</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho2</span><span class="p">,</span> <span class="n">C2</span><span class="p">))</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">].</span><span class="n">set_title</span><span class="p">(</span><span class="sa">f</span><span class="s">"pho = </span><span class="si">{</span><span class="n">pho2</span><span class="si">}</span><span class="s">"</span><span class="p">)</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">].</span><span class="n">set_xlabel</span><span class="p">(</span><span class="s">"distance (m)"</span><span class="p">)</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">].</span><span class="n">plot</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">potential_pho3</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho3</span><span class="p">,</span> <span class="n">C2</span><span class="p">))</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">].</span><span class="n">set_title</span><span class="p">(</span><span class="sa">f</span><span class="s">"pho = </span><span class="si">{</span><span class="n">pho3</span><span class="si">}</span><span class="s">"</span><span class="p">)</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">].</span><span class="n">set_xlabel</span><span class="p">(</span><span class="s">"distance (m)"</span><span class="p">)</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">].</span><span class="n">plot</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">potential_pho4</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">C1_pho4</span><span class="p">,</span> <span class="n">C2</span><span class="p">))</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">].</span><span class="n">set_title</span><span class="p">(</span><span class="sa">f</span><span class="s">"pho = </span><span class="si">{</span><span class="n">pho4</span><span class="si">}</span><span class="s">"</span><span class="p">)</span>
<span class="n">axis</span><span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">].</span><span class="n">set_xlabel</span><span class="p">(</span><span class="s">"distance (m)"</span><span class="p">)</span>

<span class="n">plt</span><span class="p">.</span><span class="n">show</span><span class="p">()</span>
</code></pre></div></div>
<p><img src="https://coolest-tomato.github.io\images\2025-02-18-Electromagnetism_1\asd-1740195440661-16.png" alt="asd" /></p>]]></content><author><name>Shim, 심장현</name></author><summary type="html"><![CDATA[import numpy as np import matplotlib.pyplot as plt import math]]></summary></entry></feed>