“...... Therefore, the Helmholtz equation is bounded in a certain region, and in the waveguide, the solution of the equation can be expressed by a linear combination of discrete eigenmodes due to the limitation of boundary conditions. ”

"As for the compact differential format, it's even simpler, it's a finite difference method with high accuracy. For example......

However, the differential format used to approximate the partial derivative at discrete point xi involves at least 1 ...... of grid points larger than the order of the truncation error of this differential format Also, the differential format is shown to have a high degree of numerical dispersion. The compact difference format is different from the difference format shown above, which uses the weighted average of the function values on several points near the grid point xi to approximate the weighted average of the partial derivative of the function at several grid points near the grid point xi. ”

Cheng Nuo told the three of them his opinions like a few treasures. The three people on the side were stunned when they heard it.

At the end, Cheng Nuo looked up at Wang Genji very humbly, and said with a sincere attitude of wanting to ask for advice, "Senior, these things are just a little humble opinion of mine. There must still be many deficiencies, and I hope that the seniors will teach me. ”

Wang Genji: "......"

Teach, teach, teach!

Wang Genji looked at Cheng Nuo with speechless eyes at this time, the wind was messy, and he didn't know what to say.

"Helmholtz equation" and "compact difference format" are the two most important keywords of their project.

In fact, before the topic was sent to them, Wang Genji, a junior in the School of Mathematics, had only heard of these two rankings.

It's the kind I've really heard of, and I've only heard the name. It's not that Cheng Nuo's pretending to be forced "has heard a little".

To be honest, Wang Genji even doubted it. In the concept of the two, the level represented by a little hearing is completely different.

The large number of things that Cheng Nuo said alone cannot be summed up in the words "a little heard".

Cheng Nuo talked over there for more than ten minutes, but Wang Genji listened carefully throughout the whole process.

It can be said that what Cheng Nuo said is not the slightest mistake and is also very comprehensive. There are even some things that Wang Genji, who has been studying this topic for more than a month, does not understand.

As for teaching......

Wang Genji looked at his other two comrades with a bitter face, as if he was begging for help.

Help, brothers!

And the two of them didn't seem to feel Wang Genji's gaze.

Zhuang Poxiao: "Senior brother, let's go to the first floor of the cafeteria together for lunch, I heard that there is a new window of choice, and it tastes good." ”

Jiang Shuobo: "Well, this is good, let's go over together in a while." ”

Wang Genji: "Hehe......"

What about the friendship that is good?

"Senior Foundation, are you okay?" Cheng Nuo asked out loud when he saw Wang Jiji's constipated expression. "Actually, I have a few bottles of kidney treasure in my dorm room. Or I'll bring it to you next time. Liuwei Rehmannia pills are also available. ”

"......" Wang Genji waved his hand, "I'm fine, let's continue." ”

Wang Genji turned around, carrying his hands behind his back, with an unfathomable look, "About these two terms, in fact, what you know is only scratching the surface. I won't say anything about teaching. Because even if I did, I am afraid that you will not be able to understand it for a while. I have never advocated cramming education. ”

"So, for the rest of the year, you can follow the three of us and delve into this project. It is estimated that by the end of the project, you will have a deeper understanding of the two terms. ”

Cheng Nuo's standard budding junior nodded obediently, "Okay, senior." ”

It's so dangerous, the senior's face is finally saved.

Wang Genji wiped a handful of sweat from his forehead.

"Senior, what is my specific task?" Cheng Nuo asked, and then added, "By the way, and the research progress of this topic?"

Wang Genji turned around, sat opposite Cheng Nuo, scratched his head, and said with some embarrassment, "For more than a month, because the three of us are busy with other things, we are currently ...... We're just putting together the general framework of the project. ”

"As for the specific content filling, if you count according to the progress, it is not enough...... 5%。 ”

Cheng Nuo rolled his eyes, speechless.

Twenty-one progress!

The scientific research time of this project is less than five months. More than a month has passed, but the progress of the project is currently only 5%.

It seems that in the later time, everyone wants to go home for a good New Year, and it is almost impossible not to explode the liver.

Jiang Shuobo, as the deputy leader of this research group, coughed lightly and spoke slowly.

"The four of us are together today, and the time when the three of us were busy should have passed. And Cheng Nuo, you are now a freshman, and you have plenty of time after class. ”

"Now, I'll give you a little bit of a task. ”

Naturally, such a complex project cannot be done by one person from beginning to end. The division of labor and cooperation and mutual coordination are necessary at this time.

Jiang Shuobo turned his head to Cheng Nuo and said, "As I said just now, we have completed the general framework of this project. ”

"This project, in fact, can be divided into five main parts. ”

"The first part, and the most basic part, is to obtain a linear system of two-dimensional Helmholtz equations by combining the one-dimensional Helmholtz equation with the compact difference format. Cheng Nuo, this is the easiest part of the five, I'll leave it to you, no problem, right?"

Cheng Nuo nodded, "No problem." ”

"The second part, the deficit correction of the coefficient matrix, i.e., ...... This part is left to the foundation to you. You're the best at it. ”

"Don't worry, leave it to me. Wang Genji patted his chest.

"The third part is to calculate the cyclic preprocessor and the convergence analysis. ”

"In the fourth part, the algorithm is solved with a preprocessing system. ”

"The fifth part is to experiment with numerical values. ”

"Three, four, five, these three parts can be combined into one, and I will study it with Dawn. ”

Zhuang Poxiao nodded and agreed.

"The time is tight and the task is heavy, and I hope that we can all work hard and strive to go upstream! ”

"Come on!"

The palms of the four people were stacked together, cheering and cheering.

"Senior, then, can I ask a cheesy question?" Cheng Nuo said.

"Speak. ”

"How much is the research funding for our project?"

"Ten thousand. To be exact, it is 10,000 and 71 cents. ”

Cheng Nuo: "......"

How can there be a whole thing?!

"Can't we, it's also a national-level project, just a little funding?"

"It's nice to have the money. Our project is a pure mathematics project, which uses mathematical methods to solve mathematical problems. There are no physical chemistry topics that burn money. It's good to be able to give so much. ”

"By the way, I forgot. I'll take out a thousand yuan from the scientific research funds in a while, Cheng Nuo, you go to the bookstore with Gengji in the afternoon and buy all the books on this list. ”

Jiang Shuobo waved his hand, looking wealthy.

"When we do a project, we have to look like we are doing a project. It's also inconvenient to go to the library all the time to borrow books. Since you can't use the money anywhere else, go for it...... Buy books!"