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先日も X にポストしましたが、これ Ctrl + A, Ctrl + I
コードを書き加えながら定期的に手癖で Ctrl + A, Ctrl + I。for ループ書き直しているときなどインデント乱れがちですのでよく使います。
「これは、昨日知りたかったやつ。。便利!」(X
「めっちゃ使ってるこれ会社の人に教えたら「今までスペースキーで頑張ってたのはいったい…」て膝から崩れ落ちるような感じになってた」(X
そんな声がありました。
普段使っているショートカットキーも他の人にとっては未知なものかも。ここで共有してコード書きの効率あげていきましょう!
michio
michio
Última actividad el 2 de Jun. de 2025

昨日 5/29 にお台場で MATLAB EXPO が開催されました。ご参加くださった方々ありがとうございました!
私は AI 関連のデモ展示で解説員としても立っておりましたが、立ち寄ってくださる方が絶えず、ずっと喋り続けてました。また、講演後に「さっきのすごくね?」という会話が漏れ聞こえてきたのがハイライト。
参加されたみなさま、印象に残ったこと・気になった講演・ポスター・デモ・新機能等あったら教えてください!(次回に向けて運営面での感想も)
I want to use Simulink for model-based development of the TC3XX series development board, but I am not sure about the development process and toolchain? Is there a free toolchain available for me to use? Do you have a detailed development tutorial?
以前のEXPOでも参加・聴講したことがある
67%
知り合いから聞いた
0%
MathWorksからのプロモーション,EXPOサイトで知った
0%
今年のEXPO会場でたまたま見かけた
0%
ライトニングトークって何?
33%
3 votos
Md Arif
Md Arif
Última actividad el 14 de Mayo de 2025

FFT

I have a pressure vs. time plot resulting from the input of an elastic wave, which I obtained from an Abaqus simulation. So, I have access to all the data. Now, I want to convert this time-domain graph into a frequency-domain graph using FFT in MATLAB.
I came across a code through ChatGPT, but I’m not fully confident in relying on it. Could anyone kindly clarify whether the formulas used for FFT in MATLAB are universal for all types of signals? Or is there a more effective and reliable method I should consider for this purpose?
Goncalo
Goncalo
Última actividad el 7 de Mayo de 2025

Hi guys!
Im doing a project where i need to simulate a ship connected to the grid. I have a grid->converter AC-DC-AC -> dynamic load. My converter has to keep the voltage consistent and what changes is the current. Can somebody help me?
Large Languge model with MATLAB, a free add-on that lets you access LLMs from OpenAI, Azure, amd Ollama (to use local models) on MATLAB, has been updated to support OpenAI GPT-4.1, GPT-4.1 mini, and GPT-4.1 nano.
According to OpenAI, "These models outperform GPT‑4o and GPT‑4o mini across the board, with major gains in coding and instruction following. They also have larger context windows—supporting up to 1 million tokens of context—and are able to better use that context with improved long-context comprehension."
You can follow this tutorial to create your own chatbot with LLMs with MATLAB.
What would you build with the latest update?
Christos
Christos
Última actividad el 1 de Mayo de 2025

I have a SG
F1 Starter Kit and I would like some help in order to upload my data (Temp and Humidy) to my channel
Provide insightful answers
9%
Provide label-AI answer
9%
Provide answer by both AI and human
21%
Do not use AI for answers
46%
Give a button "chat with copilot"
10%
use AI to draft better qustions
5%
1561 votos
xingxingcui
xingxingcui
Última actividad el 29 de Mzo. de 2025

看到知乎有用Origin软件绘制3D瀑布图,觉得挺美观的,突然也想用MATLAB复现一样的图,借助ChatGPT,很容易写出代码,相对Origin软件,无需手动干预调整图像属性,代码控制性强:
%% 清理环境
close all; clear; clc;
%% 模拟时间序列
t = linspace(0,12,200); % 时间从 0 到 12,分 200 个点
% 下面构造一些模拟的"峰状"数据,用于演示
% 你可以根据需要替换成自己的真实数据
rng(0); % 固定随机种子,方便复现
baseIntensity = -20; % 强度基线(z 轴的最低值)
numSamples = 5; % 样本数量
yOffsets = linspace(20,140,numSamples); % 不同样本在 y 轴上的偏移
colors = [ ...
0.8 0.2 0.2; % 红
0.2 0.8 0.2; % 绿
0.2 0.2 0.8; % 蓝
0.9 0.7 0.2; % 金黄
0.6 0.4 0.7]; % 紫
% 构造一些带多个峰的模拟数据
dataMatrix = zeros(numSamples, length(t));
for i = 1:numSamples
% 随机峰参数
peakPositions = randperm(length(t),3); % 三个峰位置
intensities = zeros(size(t));
for pk = 1:3
center = peakPositions(pk);
width = 10 + 10*rand; % 峰宽
height = 100 + 50*rand; % 峰高
% 高斯峰
intensities = intensities + height*exp(-((1:length(t))-center).^2/(2*width^2));
end
% 再加一些小随机扰动
intensities = intensities + 10*randn(size(t));
dataMatrix(i,:) = intensities;
end
%% 开始绘图
figure('Color','w','Position',[100 100 800 600],'Theme','light');
hold on; box on; grid on;
for i = 1:numSamples
% 构造 fill3 的多边形顶点
xPatch = [t, fliplr(t)];
yPatch = [yOffsets(i)*ones(size(t)), fliplr(yOffsets(i)*ones(size(t)))];
zPatch = [dataMatrix(i,:), baseIntensity*ones(size(t))];
% 使用 fill3 填充面积
hFill = fill3(xPatch, yPatch, zPatch, colors(i,:));
set(hFill,'FaceAlpha',0.8,'EdgeColor','none'); % 调整透明度、去除边框
% 在每条曲线尾部标注 Sample i
text(t(end)+0.3, yOffsets(i), dataMatrix(i,end), ...
['Sample ' num2str(i)], 'FontSize',10, ...
'HorizontalAlignment','left','VerticalAlignment','middle');
end
%% 坐标轴与视角设置
xlim([0 12]);
ylim([0 160]);
zlim([-20 350]);
xlabel('Time (sec)','FontWeight','bold');
ylabel('Frequency (Hz)','FontWeight','bold');
zlabel('Intensity','FontWeight','bold');
% 设置刻度(根据需要微调)
set(gca,'XTick',0:2:12, ...
'YTick',0:40:160, ...
'ZTick',-20:40:200);
% 设置视角(az = 水平旋转,el = 垂直旋转)
view([211 21]);
% 让三维坐标轴在后方
set(gca,'Projection','perspective');
% 如果想去掉默认的坐标轴线,也可以尝试
% set(gca,'BoxStyle','full','LineWidth',1.2);
%% 可选:在后方添加一个浅色网格平面 (示例)
% 这个与题图右上方的网格类似
[Xplane,Yplane] = meshgrid([0 12],[0 160]);
Zplane = baseIntensity*ones(size(Xplane)); % 在 Z = -20 处画一个竖直面的框
surf(Xplane, Yplane, Zplane, ...
'FaceColor',[0.95 0.95 0.9], ...
'EdgeColor','k','FaceAlpha',0.3);
%% 进一步美化(可根据需求调整)
title('3D Stacked Plot Example','FontSize',12);
constantplane("x",12,FaceColor=rand(1,3),FaceAlpha=0.5);
constantplane("y",0,FaceColor=rand(1,3),FaceAlpha=0.5);
constantplane("z",-19,FaceColor=rand(1,3),FaceAlpha=0.5);
hold off;
Have fun! Enjoy yourself!
David
David
Última actividad el 24 de Mzo. de 2025

We are excited to announce the first edition of the MathWorks AI Challenge. You’re invited to submit innovative solutions to challenges in the field of artificial intelligence. Choose a project from our curated list and submit your solution for a chance to win up to $1,000 (USD). Showcase your creativity and contribute to the advancement of AI technology.
Hello ThingSpeak Community,
I have an energy meter sending data of energy consumed in 4 rooms in hexadecimal values to Sigfox and I was trying to decode the payload and route it to ThingSpeak.
All the datas are sent at the same time.
But ThingSpeak only receives 1 of them and plots them.
However, the rest 3 are missing. Is this because I am trying the free version ?
Would the payed version be capable of receiving all the 4 messages ?
imad
imad
Última actividad el 14 de Feb. de 2025

Simulink has been an essential tool for modeling and simulating dynamic systems in MATLAB. With the continuous advancements in AI, automation, and real-time simulation, I’m curious about what the future holds for Simulink.
What improvements or new features do you think Simulink will have in the coming years? Will AI-driven modeling, cloud-based simulation, or improved hardware integration shape the next generation of Simulink?
Matthias
Matthias
Última actividad el 6 de Feb. de 2025

I noticed recently that my data is no longer updating on thingspeak again. Is there a connectivity issues with thingspeak

Rajendrra
Rajendrra
Última actividad el 6 de Feb. de 2025

my code is as below:
#include "DHT.h"
#define DHTPIN 15 // what pin we're connected to
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);
#define THINGSPEAK_API_KEY "1P4RY69D3YMP9R5W"
#include <SoftwareSerial.h>
#include <OneWire.h>
#include <DallasTemperature.h>
//-----------------------------
#include <ArduinoJson.h>
StaticJsonDocument<200>JsonDocument;
SoftwareSerialmyserial(10, 11);
//-------------------------
float voltage;
unsignedintfrac;
//---------------------
#define ONE_WIRE_BUS 5
OneWireoneWire(ONE_WIRE_BUS);
DallasTemperaturesensors(&oneWire);
floatCelcius = 0;
float Fahrenheit = 0;
//==========================================================================================================
bytesensorInterrupt = 0; // 0 = digital pin 2
bytesensorPin = 2;
// The hall-effect flow sensor outputs approximately 4.5 pulses per second per
// litre/minute of flow.
floatcalibrationFactor = 5.5; //==========================================================we change cal factor 4.5 to 5.5 if not work chnage again(4.5)
//========== 5.5 calibration factor is working efficent then 4.5 , 7.5 ,and 6.5
volatile byte pulseCount;
floatflowRate;
unsignedintflowMilliLitres;
unsigned long totalMilliLitres, tempTotal = -1;
unsigned long oldTime;
//-------------------------------------------------------
intpH_Value;
float Voltage;
//----------------------------------------------------------------------------------------------
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
myserial.begin(9600);
//--------------------------------
pinMode(sensorPin, INPUT);
digitalWrite(sensorPin, HIGH);
pulseCount = 0;
flowRate = 0.0;
flowMilliLitres = 0;
totalMilliLitres = 0; // ============================================================
oldTime = 0;
attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
sensors.begin();
//------------------------------------------------
/********************GSM Communication Starts********************/
if (myserial.available())
Serial.write(myserial.read());
myserial.println("AT");
delay(1000);
myserial.println("AT+SAPBR=3,1,\"Contype\",\"GPRS\"");
delay(1000);
ShowSerialData();
myserial.println("AT+SAPBR=3,1,\"APN\",\"www\"");//APN
delay(1000);
ShowSerialData();
myserial.println("AT+SAPBR=1,1");
delay(1000);
ShowSerialData();
myserial.println("AT+SAPBR=2,1");
delay(1000);
ShowSerialData();
//---------------------------------
}
void loop() {
// put your main code here, to run repeatedly:
inti;
for (i = 0; i< 20; i++)
{
flow_meter();
}
temperature();
turbidity();
delay(1000);
gsm();
}
voidflow_meter()
{
if ((millis() - oldTime) > 1000) // Only process counters once per second
{
// Disable the interrupt while calculating flow rate and sending the value to
// the host
detachInterrupt(sensorInterrupt);
// Because this loop may not complete in exactly 1 second intervals we calculate
// the number of milliseconds that have passed since the last execution and use
// that to scale the output. We also apply the calibrationFactor to scale the output
// based on the number of pulses per second per units of measure (litres/minute in
// this case) coming from the sensor.
flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
// Note the time this processing pass was executed. Note that because we've
// disabled interrupts the millis() function won't actually be incrementing right
// at this point, but it will still return the value it was set to just before
// interrupts went away.
oldTime = millis();
// Divide the flow rate in litres/minute by 60 to determine how many litres have
// passed through the sensor in this 1 second interval, then multiply by 1000 to
// convert to millilitres.
flowMilliLitres = (flowRate / 60) * 1000;
// Add the millilitres passed in this second to the cumulative total
totalMilliLitres += flowMilliLitres;
// Print the flow rate for this second in litres / minute
/* Serial.print("Flow rate: ");
Serial.print(int(flowRate)); // Print the integer part of the variable
Serial.print("."); // Print the decimal point */
// Determine the fractional part. The 10 multiplier gives us 1 decimal place.
frac = (flowRate - int(flowRate)) * 10;
Serial.print(frac, DEC) ; // Print the fractional part of the variable
Serial.println("L/min");
/* // Print the number of litres flowed in this second
Serial.print(" Current Liquid Flowing: "); // Output separator
Serial.print(flowMilliLitres);
Serial.print("mL/Sec");
// Print the cumulative total of litres flowed since starting
Serial.print(" Output Liquid Quantity: "); // Output separator
Serial.print(totalMilliLitres);
Serial.println("mL"); */
if ( tempTotal != totalMilliLitres ) {
tempTotal = totalMilliLitres;
// displayVolumeOfWater(totalMilliLitres );
}
// Reset the pulse counter so we can start incrementing again
pulseCount = 0;
// Enable the interrupt again now that we've finished sending output
attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
}
//=========================================================================================================================
}
voidpulseCounter()
{
// Increment the pulse counter
pulseCount++;
}
//-------------------------------------------------------------------------
void temperature()
{
sensors.requestTemperatures();
Celcius = sensors.getTempCByIndex(0);
Fahrenheit = sensors.toFahrenheit(Celcius);
Serial.print(" C ");
Serial.print(Celcius);
// Serial.print(" F ");
// Serial.println(Fahrenheit);
delay(1000);
}
//------------------------------------------------------------
void turbidity()
{
intsensorValue = analogRead(A0);
voltage = sensorValue * (5.0 / 1024.0);
// Serial.println ("Sensor Output (V):");
Serial.println (voltage);
// Serial.println();
delay(1000);
}
//------------------------------------------------------------
voidgsm()
{
myserial.println("AT+HTTPINIT");
delay(1000);
ShowSerialData();
myserial.println("AT+HTTPPARA=\"CID\",1");
delay(1000);
ShowSerialData();
StaticJsonDocument<200>JsonDocument;
JsonObject& object = JsonDocument.createObject();
object.set("TE", Celcius);
object.set("TU", voltage);
object.set("WF", frac);
delay(1000);
object.printTo(Serial);
Serial.println(" ");
String sendtoserver;
object.prettyPrintTo(sendtoserver);
delay(1000);
//myserial.println("AT+HTTPPARA=\"URL\",\"https://api.thingspeak.com/update?api_key=\""); //Server address
myserial.println("AT+HTTPPARA=\"URL\",\"https://api.thingspeak.com/update?api_key=\""); //Server address
delay(1000);
ShowSerialData();
myserial.println("AT+HTTPPARA=\"CONTENT\",\"application/json\"");
delay(1000);
ShowSerialData();
myserial.println("AT+HTTPDATA=" + String(sendtoserver.length()) + ",100000");
Serial.println(sendtoserver);
delay(1000);
ShowSerialData();
myserial.println(sendtoserver);
delay(2000);
ShowSerialData;
myserial.println("AT+HTTPACTION=1");
delay(1000);
ShowSerialData();
myserial.println("AT+HTTPREAD");
delay(1000);
ShowSerialData();
myserial.println("AT+HTTPTERM");
delay(1000);
ShowSerialData;
}
voidShowSerialData()
{
while (myserial.available() != 0)
Serial.write(myserial.read());
delay(1000);
}
You've probably heard about the DeepSeek AI models by now. Did you know you can run them on your own machine (assuming its powerful enough) and interact with them on MATLAB?
In my latest blog post, I install and run one of the smaller models and start playing with it using MATLAB.
Larger models wouldn't be any different to use assuming you have a big enough machine...and for the largest models you'll need a HUGE machine!
Even tiny models, like the 1.5 billion parameter one I demonstrate in the blog post, can be used to demonstrate and teach things about LLM-based technologies.
Have a play. Let me know what you think.
Bernard P S
Bernard P S
Última actividad el 27 de En. de 2025

Need code to collect data of waterflow sensor using ESP 8266 and to stoe it in ThingSpeak cloud
Ciao a Tutti,qualche mese fa avevo costruito una stazione meteo con un esp32 e vari sensori.
Tutto funzionava, adesso però ho riprovato, e non funziona più. Ho provato a creare un canale nuovo con nuovo ID canale, nuovo ID Client, nuovo Utente (uguale al Client) e nuova Password. si connette (ho inserito un comando se connesso a MQTT scrivi.....) ma non publica i dati.
Non reisco a saltarne fuori, ècambiato qualche cosa?
grazie a tutti
Manfred Kreidl
Manfred Kreidl
Última actividad el 27 de En. de 2025

Hello,
could it be that there is currently is a stability problem with the MQTT-Broker? I can establisth a connection successfully using the MQTTX client (web and win64 installation). I tried all possible ports an connection types. It disconnects all the time after a few seconds of establishing a connection successfully. So it was not possible to subscribe any item. I do not think the problem is in my side... By the way, protocol verision 3.1.1 ist supported, 5.0 not, am I right?
Maybe you could give me a hint,
Best regards,
Manfred
私の場合、前の会社が音楽認識アプリの会社で、アルゴリズム開発でFFTが使われていたことがきっかけでした。でも、MATLABのすごさが分かったのは、機械学習のオンライン講座で、Andrew Ngが、線型代数を使うと、数式と非常に近い構文のコードで問題が処理できることを学んだ時でした。