◆ MATLAB

Use Fourier analysis for time series prediction

This is real work, not a feature someone invented — it comes from real job ads and real questions people asked. Below are four ready AI prompts: get it done, make it easy for the next person to say yes to, work out the right move when you are stuck, and stop it coming back.

4prompts

The same task, four prompts

today's deadline · the next reviewer · the stuck moment · the pattern
AExecute — do the immediate taskApply a Fast Fourier Transform to the 'sensor_data' time series and plot the magnitude…+
Apply a Fast Fourier Transform to the 'sensor_data' time series and plot the magnitude spectrum.
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?
BImprove — make it easier to acceptBefore I share these results with the operations team, make the key frequencies in the…+
Before I share these results with the operations team, make the key frequencies in the 'machine_vibration' data obvious. Highlight the dominant frequency with an annotation, filter out any noise below 1 Hz, and ensure the x-axis is labeled in actual Hertz so they can relate it to machine RPMs.
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?
CDecide — diagnose the stuck momentMy Fourier analysis for predicting the next 24 hours of 'energy_demand' just ran, and the…+
The predicted future values from my Fourier model are wildly inaccurate compared to the last week's actuals.
My Fourier analysis for predicting the next 24 hours of 'energy_demand' just ran, and the predictions are completely off from the actuals we saw last week. I'm worried I've either used the wrong number of components or my input data has a fundamental issue. What's the most common pitfall when Fourier predictions fail this badly, and what's the first diagnostic step I should take before I report this to the plant manager?
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?
DBecome — change the patternI consistently lose time trying to select the optimal number of Fourier components for time…+
I frequently struggle to decide on the right number of Fourier components for accurate predictions.
I consistently lose time trying to select the optimal number of Fourier components for time series predictions, often over-fitting or under-fitting the data. What habit should I change to more systematically determine the appropriate model complexity for 'stock_price' or 'weather_pattern' data without relying on trial and error?
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?

Questions people actually ask

honest answers, no sign-up

Every task here was seen in the real world. Someone doing the job named it, a real job ad asked for it, or a lot of people asked about it online.

If nothing real showed a task, it is not on the page. That is the whole rule.

They are the same job approached four ways, because what you need depends on where you are.

Get it done today. Make it easy for the next person to say yes to. Work out the right move when you are stuck. Learn the pattern so the job stops coming back.

For most of these jobs it can carry the heavy thinking - draft it, sort it, check it, rehearse it with you.

It cannot sit in your chair, take the blame when a number is wrong, or notice what nobody wrote down. Let it do the first 80%. Keep the last 20% that is truly yours.

No. Copy any prompt and paste it into the AI you already use. No account, no score, no wall in the way.

Any of them. The prompts describe the work rather than naming a product, so they are not tied to one assistant.

That is also why they keep working when you switch.

Change it freely. Every prompt is a starting line, not a rule.

Put in your real numbers, your real names and your real deadline. The more you make it yours, the better the answer comes back.

The tasks come from real job ads, published job data and the questions people ask in public forums.

The steps come from MATLAB's own documentation, with practitioner sources for the traps the manual does not mention.

Push once. Ask it to sharpen the weakest part and to say what it assumed.

Most wrong answers come from a missing detail rather than a bad prompt - tell it the thing it could not know.